Liquid crystal display device and electronic apparatus

ABSTRACT

The present invention provides a color transflective liquid crystal display that is capable of display with good coloring and high visibility in both a reflective mode and a transmissive mode while suppressing deterioration in color reproduction caused by unevenness of the spectral properties of the illumination light, if any. The liquid crystal display can include a liquid crystal display panel including pixels formed of a plurality of sub-pixels each corresponding to different colors, and an illumination device, wherein the liquid crystal display panel includes a transflective layer and a color filter of color corresponding to each of the sub-pixels. The transflective layer includes transmissive portions for transmitting illumination light, wherein the transmissive portion is formed such that the dimension of the transmissive area corresponding to the transmissive portion of at least one sub-pixel out of the plurality of sub-pixels and the dimension of the transmissive area corresponding to the transmissive portion of another sub-pixel, differ.

This is a Continuation of application Ser. No. 11/119,728 filed May 3,2005, which in turn is a Divisional of application Ser. No. 10/006,660filed Dec. 10, 2001 now U.S. Pat. No. 6,909,479. The disclosure of theprior applications is hereby incorporated by reference herein in itsentirety.

BACKGROUND OF THE INVENTION

1. Field of Invention

The present invention relates to a liquid crystal display and toelectronic apparatus, and particularly relates to a transflective liquidcrystal display capable of display with good coloring and highvisibility in both reflective mode and transmissive mode, and alsorelates to an electronic apparatus using the same.

2. Description of Related Art

Currently, reflective liquid crystal displays are advantageous in thatelectric power consumption is low, since they do not have light sourcessuch as back-lights, and have conventionally been widely used asaccessory display units or the like for various types of mobileelectronic apparatus and so forth. However, reflective liquid crystaldisplays use external light, such as natural light like sunlight, orillumination light, to perform display. Accordingly, reflective liquidcrystal displays can suffer from the disadvantage that the display isnot readily visually recognized in dark situations.

Accordingly, liquid crystal displays have been proposed wherein externallight is used in bright situations in the same manner as with standardreflective liquid crystal displays, and an internal light source such asa back-light is used in dark situations so as to make the displayvisible. In other words, this liquid crystal displays employs a displaymethod serving as both reflective type and transmissive type. Thedisplay method can be switched between a reflective mode andtransmissive mode according to the surrounding brightness, therebyenabling a clear display even in dark situations while reducing electricpower consumption. Thus, external light contributes to display in areflection type display, and light emitted from an illumination device(back-light) (this light hereafter referred to as “illumination light”)contributes to display in a transmissive display. In the presentspecification, this type of liquid crystal display will be referred toas “transflective liquid crystal display”.

A transflective liquid crystal display generally includes a liquidcrystal display panel wherein liquid crystals are sandwiched between apair of substrates, and an illumination device provided on the oppositeside of the liquid crystal display panel in relation to the observationside for casting light on the substrate face of the liquid crystaldisplay panel. Further, a reflective layer (transflective layer)including a plurality of opening portions is disposed on the substrateat the opposite side of the liquid crystal display panel in relation tothe observation side.

Also, in recent years, advancements in mobile electronic apparatuses andoffice automation equipment has come to demand colorization of liquidcrystal displays. In many cases, colorization is requested fromelectronic apparatuses including the above-described transflectiveliquid crystal display, as well.

As for a color transflective liquid crystal display to meet thesedemands, a transflective liquid crystal display having a color filterhas been proposed . Such a color transflective liquid crystal displaywith a color filter is arranged such that external light entering theliquid crystal display in the reflective mode passes through the colorfilter, is reflected by the reflector, and passes through the colorfilter again. Also, in the transmissive mode, light from the back-lightalso passes through the color filter. The same color filter is used forboth the reflective mode and the transmissive mode.

SUMMARY OF THE INVENTION

With the above-described color transflective liquid crystal displays,light passes through the color filter twice in the reflective mode andonce in the transmissive mode, thereby realizing a color display asdescribed above.

Accordingly, in the event that importance is given to display in thereflective mode where light passes through the color filter twice, forexample, and accordingly a color filter with light colors is provided,display with good coloring cannot be readily obtained in thetransmissive mode wherein the light passes through the color filter onlyonce. However, in the event that, in an attempt to solve this problem,importance is given to the transmissive mode where light passes throughthe color filter once, and accordingly a color filter with dark colorsis provided, the display in the reflective mode where light passesthrough the color filter twice becomes dark, and consequently sufficientvisibility cannot be obtained. Thus, with conventional colortransflective liquid crystal displays, it has been difficult to obtain adisplay with good coloring and high visibility both in the reflectivemode and transmissive mode.

Also, illumination light emitted from illumination devices comprisingLEDs (Light Emitting Diode) or cold cathode tubes or the like as a lightsource often do not have uniform luminance (intensity) throughout allwavelengths in the visible light range. Using such light withnon-uniform distribution in luminance to perform transmissive displaycan result also in nonuniformity of the spectral properties of lightpassing through the liquid crystal display panel and emitted towards theobservation. As a result, there has been the problem of deterioration incolor reproduction that the display will be bluish in the case of usingillumination light that has higher luminance in the wavelengthcorresponding to the blue color as compared to the luminance of otherwavelengths, for example, to perform transmissive display.

The present invention has been made in view of the above problems, andaccordingly it is an object thereof to provide a color transflectiveliquid crystal display wherein, even in the event that the spectralproperties of the illumination light used for transmissive display arenot uniform, resultant deterioration in color reproduction can besuppressed. Also, with the color transflective liquid crystal displayemploying both a reflective mode and a transmissive mode, display withgood coloring and high visibility can be obtained both in the reflectivemode and transmissive mode.

Also, it is an object of the present invention to provide an electronicapparatus including the above-described liquid crystal display withexcellent visibility.

A liquid crystal display according to the present invention can includea liquid crystal display panel formed of liquid crystals sandwichedbetween a pair of substrates facing each other, and further includepixels having a plurality of sub-pixels each corresponding to differentcolors. The display can also include an illumination device provided tothe opposite side of the liquid crystal display panel in relation to theobservation side for illuminating the liquid crystal display panel withillumination light. The liquid crystal display also has a transflectivelayer disposed on the opposite side of the liquid crystals in relationto the observation side with a transmissive portion for transmitting theillumination light formed thereto, wherein the transmissive portion isformed such that the dimension of a transmissive area corresponding tothe transmissive portion at least at one sub-pixel out of the pluralityof sub pixels, and the dimension of a transmissive area corresponding tothe transmissive portion at another sub-pixel, differ, and a colorfilter provided corresponding to each of the sub-pixels, fortransmitting light of a wavelength corresponding to a color of thesub-pixel.

According to this liquid crystal display, the percentage of transmissivearea of any one of the plurality of sub-pixels forming the pixels ismade to differ from the percentage of transmissive area of othersub-pixels, thereby enabling the essential light transmittance of thesub-pixels as to the illumination light of the illumination device to bearbitrarily selected. Accordingly, even in the event that there areirregularities in the spectral properties of the illumination light(luminance and quantity of light of the illumination light at eachwavelength, spectral energy, etc.), the irregularities of the spectralproperties of the light emitted from the liquid crystal display paneltowards the observation side can be reduced by compensating for theirregularities. Further, the percentage of the transmissive area ofsub-pixels of one of the colors can be intentionally increased for acolor of display by the liquid crystal display panel to be selected.

Now, with the present invention, the dimension of the transmissive areaat each sub-pixel is preferably a dimension according to the spectralproperties of the illumination light. Even in the event that there areirregularities in spectral properties of the illumination light, makingthe percentage of transmissive area at each sub-pixel be a percentageaccording to the spectral properties compensates for the irregularities,and excellent color reproduction can be realized. Specifically, anarrangement may be conceived wherein the dimension of the transmissivearea at each sub-pixel is a dimension according to the luminance of thewavelength of the illumination light corresponding to the color of thesub-pixel. That is, making the dimension of the transmissive area at asub-pixel of a color corresponding to a wavelength of the illuminationlight with great luminance be smaller than the dimension of thetransmissive area at a sub-pixel of a color corresponding to awavelength of the illumination light with small luminance, light in theillumination light with more luminance can be made to have relativelyless luminance in the observation light. On the other hand, light in theillumination light with less luminance can be made to have relativelymore luminance in the observation light. In this case, making thedimension of the transmissive area at each of the sub-pixels differ foreach sub-pixel corresponding to a different color (i.e., such that thedimension of the transmissive area is the same for sub-pixelscorresponding to the same color) is advantageous in simplifyingconfiguration.

Also, a case may be conceived wherein the spectral properties of theillumination light differ according to the position within the substrateface of the liquid crystal display panel. In this case, the dimension ofthe transmissive area at each of the sub-pixels is preferably made todiffer in configuration according to the position of the sub-pixelwithin the substrate face of the liquid crystal display panel. Thisarrangement allows the irregularities in spectral properties of theillumination light within the substrate face (i.e., inconsistenciesbetween the spectral properties at one position within the substrateface and spectral properties at another position) to be compensated, sothat color reproduction can be more reliably improved.

Also, a configuration for the transmissive portion may be conceivedwherein an opening portion corresponding to each of the sub-pixels isformed in the transflective layer. When this configuration is employed,the opening portion can be formed by removing by etching or the like apart of the transflective layer formed beforehand, and accordingly themanufacturing process can be simplified. Now, an arrangement wherein oneopening portion is provided for each sub-pixel may be conceived, but inthis case, opening portions will be concentrated on a part of the areasof the sub-pixels, which could lead to occurrence of graininess of thedisplay. In order to solve this problem, an arrangement may be conceivedwherein the opening portion comprises opening parts of generally thesame dimension that are formed mutually separated for the numberaccording to the dimension of the transmissive area at the sub-pixels.Thus, the opening portions can be dispersed over the entirety of thesub-pixel, so that occurrence of graininess, as described above, can beavoided.

Also, as a different form of the transflective layer in a liquid crystaldisplay according to the present invention, the transflective layer mayhave the transmissive portion formed such that an area along at leastone side of a plurality of sides defining each sub pixel serves as thetransmissive area.

Also, in order to achieve the above objects, the liquid crystal displayaccording to the present invention, serving as a transflective liquidcrystal display which performs displaying by switching between atransmissive mode and a reflective mode, may include a liquid crystallayer sandwiched between an upper substrate and a lower substrate facingone another, and a transflective layer which has a transmissive area fortransmitting light, and a reflective area for reflecting incident lightfrom the upper substrate side, and which is disposed on the inner sideof the lower substrate. The display can further include a color filterdisposed on the upper side of the transflective layer, upon which aplurality of pigment layers of different colors according to each ofsub-pixels forming a display area are arrayed, and an illuminationdevice disposed on the outer side of the lower substrate, wherein thepigment layers are formed over the entirety of an area overlapping thetransmissive area in a planar manner and an area overlapping thereflective area in a planar manner, and at least one color pigment layeris formed only at a part of an area overlapping the reflective area in aplanar manner. The dimension of the pigment layer formation area, wherethe pigment layers are formed, being formed so as to be differentbetween at least one color pigment layer of the plurality of pigmentlayers of differing colors, and another color pigment layer.

With such a liquid crystal display, the pigment layers can be formed onthe entire area overlapping the transmissive area in a planar manner andan area, excluding a part of the area, overlapping the reflective areain a planar manner, with a pigment layer formation area where each ofthe pigment layers is formed, and an area where each of the pigmentlayers is not provided at part of the area overlapping the reflectivearea (hereafter referred to as “pigment layer non-formation area”) in aplanar manner. A part of the incident external light entering the liquidcrystal display in the reflective mode passes through the pigment layernon-formation area, and the light passing through the color filter twicein the reflective mode is obtained as a light that combines uncoloredlight passing through the pigment layer non-formation area and coloredlight passing through the pigment layer formation area.

On the other hand, light incident from the back-light and passingthrough the transmissive area in the transmissive mode all passesthrough pigment layer formation areas, and the light passing through thecolor filter once in the transmissive mode is all obtained as coloredlight. Thus, the difference in concentration between the light obtainedby passing through the color filter twice in the reflective mode and thelight obtained by passing through the color filter once in thetransmissive mode can be reduced. Consequently, a color transflectiveliquid crystal display capable of display with good coloring and highvisibility both in the reflective mode and transmissive mode, can berealized.

Moreover, with the liquid crystal display according to the presentinvention, the dimension of the pigment layer formation area is formedto be different between a pigment layer of at least one color out of thepigment layers and pigment layers of other colors, so that the colorproperties of the color filter can be adjusted by changing the dimensionof the pigment layer formation area. Color reproduction can also beimproved, so that a liquid crystal display with excellent displayquality can be realized.

Also, with the above-described liquid crystal display, the pigmentlayers preferably can include a red layer, a green layer, and a bluelayer, with the dimension of the pigment formation area preferably beingformed so as to be smaller for the green layer than for the red layerand blue layer.

Arranging the liquid crystal display thus allows further improvement incolor reproduction in the event that the pigment layers include a redlayer, a green layer, and a blue layer, and a liquid crystal displaywith even more excellent display quality can be realized.

Also, the above-described liquid crystal display preferably furtherincludes a transparent film for smoothing the step between the pigmentlayer formation area and the area where the pigment layers are notprovided.

Arranging the liquid crystal display thus can eliminate adverse effects,such as irregularities occurring in cell gaps that causes unevenness indisplay, due to the step between the pigment layer formation area andthe area where the pigment layers are not provided, and accordingly thereliability of the liquid crystal display can be improved. With theabove-described liquid crystal display, the transmissive area is formedby the transflective layer being opened in a window-like manner.

Also, the above-described liquid crystal display may be configured suchthat band-shaped transparent electrodes are disposed on the inner sideof the lower substrate, and the transmissive area of a band shape isformed in the transflective layer by having the transparent electrodepattern width be formed wider than the transflective layer patternwidth.

In the above-described liquid crystal display, the transflective layeris preferably formed of aluminum or an aluminum alloy, with the pigmentlayer containing a blue layer, and the dimension of the pigment layerformation area being provided so as to be smaller for the blue layerthan for the red layer.

With the liquid crystal display configured thus, the dimension of thepigment layer formation area is provided so as to be smaller for theblue layer than for the red layer, so that even in the event that thelight reflected by the transflective layer is colored blue due to thetransflective layer being formed of aluminum, the light is compensatedby passing through the color filter twice. Thus, a liquid crystaldisplay with excellent color reproduction and high display quality canbe realized.

Also, in the above-described liquid crystal display, the transflectivelayer is preferably formed of silver or a silver alloy, with the pigmentlayer containing a red layer and blue layer, and the dimension of thepigment layer formation area being provided so as to be smaller for thered layer than for the blue layer.

With the liquid crystal display configured thus, the dimension of thepigment layer formation area is provided so as to be smaller for the redlayer than for the blue layer, so that even in the event that the lightreflected by the transflective layer is colored yellow due to thetransflective layer being formed of silver, the light is compensated bypassing through the color filter twice. Accordingly, a liquid crystaldisplay with excellent color reproduction and high display quality canbe realized.

Also, with the above-described liquid crystal display, the colorproperties of the color filter are preferably adjusted by changing thedimension of the pigment layer formation area.

With such a liquid crystal display, the difference in colorconcentration between the light passing through the color filter twicein the reflective mode and the light passing through the color filteronce in the transmissive mode can be reduced, while color reproductionis improved. Consequently, a color transflective liquid crystal displaycapable of display with good colorization, high visibility, andexcellent color reproduction both in the reflective mode andtransmissive mode, can be realized.

Also, in order to achieve the above objects, the liquid crystal displayaccording to the present invention, serving as a transflective liquidcrystal display which performs displaying by switching between atransmissive mode and a reflective mode, can include a liquid crystaldisplay panel formed of a liquid crystal layer sandwiched between aupper substrate and lower substrate facing each other, and includingpixels that has a plurality of sub-pixels each corresponding todifferent colors and form a display area, and an illumination deviceprovided to the opposite side (outer side of the lower substrate) of theliquid crystal display panel in relation to the observation side, forilluminating the liquid crystal display panel with illumination light.The liquid crystal display further can further include a transflectivelayer disposed on the opposite side (inner side of the lower substrate)of the liquid crystal layer in relation to the observation side, and acolor filter provided above the transflective layer with a plurality ofpigment layers of different colors corresponding to each of thesub-pixels arrayed thereupon, for transmitting light of a wavelengthcorresponding to the color of each sub-pixel. In the liquid crystaldisplay, a transmissive portion for transmitting the illumination lightis formed on the transflective layer that has a transmissive area fortransmitting light and a reflective area for reflecting incident lightfrom the upper substrate side, and the transmissive portion is formedsuch that the dimension of the transmissive area corresponding to thetransmissive portion at least at one sub-pixel of the plurality ofsub-pixels The dimension of the transmissive area corresponding to thetransmissive portion at another sub-pixel, differ. Also, in the liquidcrystal display, the pigment layers can be formed over the entirety ofan area overlapping the transmissive area in a planar manner and an areaoverlapping the reflective area in a planar manner, and at least onecolor pigment layer is formed at a part of an area overlapping thereflective area in a planar manner. Further, in the liquid crystaldisplay, the dimension of a pigment layer non-formation area where thepigment layers are not formed at least at one sub-pixel of the pluralityof sub-pixels, and the dimension of a pigment layer non-formation areaat another sub-pixel, differ.

With such a liquid crystal display, the transmissive portion can beformed such that the dimension of the transmissive area corresponding tothe transmissive portion at least at one sub-pixel of the plurality ofsub-pixels, and the dimension of the transmissive area corresponding tothe transmissive portion at another sub-pixel, differ Also the dimensionof a pigment layer non-formation area where the pigment layers are notformed at least at one sub-pixel of the plurality of sub-pixels, and thedimension of a pigment layer non-formation area at another sub-pixel,differ.

Accordingly, with such a liquid crystal display, the display colors andbrightness are adjusted by changing the ratio of the transmissive areaand reflective area in the sub-pixels, between one of the plurality ofsub-pixels and another sub-pixel. Also, the color properties of thecolor filter can be adjusted by changing the ratio of the dimension ofthe pigment layer formation area and the pigment layer non-formationarea, between at least one color pigment layer of the pigment layers andanother color pigment layer, so that the display colors and brightnessare adjusted.

With conventional transflective liquid crystal displays, increasing thetransmittance by enlarging the transmissive area such that a brightdisplay can be obtained in the transmissive mode, has the problem inthat the reflectivity decreases and the display becomes dark in thereflective mode. Thus, it has been difficult to realize a transflectiveliquid crystal display wherein a bright display can be obtained in boththe reflective mode and transmissive mode.

Conversely, with the above-described liquid crystal display, even in theevent that the transmittance is improved by enlarging the transmissivearea for a bright display to be obtained in the transmissive mode andthat the reflective area becomes small, sufficient reflectivity for abright display in the reflective mode can be obtained by enlarging thedimension of the pigment layer non-formation area. Thus, a problem doesnot occur that the display becomes dark in the reflective mode.

Thus, according to the above-described liquid crystal display, thebrightness can be effectively adjusted, and a bright display can beachieved whether in the reflective mode or the transmissive mode.

Further, with such a liquid crystal display, the display colors can beadjusted by changing the ratio of the transmissive area and reflectivearea in the sub-pixels. Also, the display colors can be adjusted bychanging the ratio of the dimension of the pigment layer formation areaand the pigment layer non-formation area for each of the pigment layersto adjust the color properties of the color filter. Accordingly, thedisplay colors can be effectively adjusted, and extremely excellentcolor reproduction can be obtained.

Moreover, the above-described liquid crystal display can include apigment layer formation area and pigment layer non-formation area, sothat the difference in concentration of color between the light passingthrough the color filter twice in the reflective mode and the lightpassing through the color filter once in the transmissive mode can bereduced. Thus, a color transflective liquid crystal display capable ofdisplay with similarly good coloring and high visibility both in thereflective mode and transmissive mode, can be realized.

Consequently, using the above-described liquid crystal display enables acolor transflective liquid crystal display with extremely excellentdisplay quality to be realized.

Also, in order to achieve the above objects, the electronic apparatusaccording to the present invention can include one of theabove-described liquid crystal displays. For example, the liquid crystaldisplay according to the present invention may be used as a displaydevice in various types of electronic apparatuses, such as televisionsor monitors, communication equipment such as cellular telephones orPDAs, information processing devices such as personal computers, and soforth. According to the electronic apparatus, even in the event thatthere are irregularities in spectral properties of the illuminationlight, this can be compensated to realize a display with high colorreproduction, thereby yielding an electronic apparatus comprising aliquid crystal display with excellent visibility. Thus, this is suitablefor an electronic apparatus requiring particularly high-quality display.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described with reference to the accompanyingdrawings, in which like elements are referred to with like numerals, andin which:

FIG. 1 is a cross-sectional diagram illustrating the configuration of aliquid crystal display according to a first embodiment of the presentinvention;

FIG. 2 is a graph illustrating spectral properties of the illuminationlight cast onto the liquid crystal display panel from the illuminationdevice in the liquid crystal display;

FIG. 3 is a plan view illustrating the positional relation between thetransparent electrodes on the first substrate and the components formedon the second substrate of the liquid crystal display;

FIG. 4 is a graph illustrating the transmittance properties of the colorfilters corresponding to each color in the liquid crystal display;

FIG. 5 is a graph illustrating spectral properties of the light passingthrough the liquid crystal display panel and emitted towards theobservation side in the liquid crystal display;

FIG. 6 is a graph illustrating spectral properties of the light passingthrough the liquid crystal display panel and emitted at the observationside in the event that all opening portions in the reflective layer areof the same dimension;

FIG. 7 is a cross-sectional diagram illustrating an example of theconfiguration of a liquid crystal display according to a secondembodiment of the present invention;

FIG. 8 is a perspective view illustrating the principal portions of theliquid crystal display panel in the liquid crystal display;

FIG. 9 is a plan view illustrating the positional relation between thepixel electrodes on the first substrate and the components formed on thesecond substrate of the liquid crystal display;

FIG. 10 is a cross-sectional diagram illustrating the configuration of aliquid crystal display according to a third embodiment of the presentinvention;

FIG. 11 is a graph illustrating the transmittance properties of thecolor filters corresponding to each color in the liquid crystal display;

FIG. 12 is a plan view illustrating the positional relation between thesub-pixels and reflective layer in the liquid crystal display;

FIG. 13 is a CIE chromaticity diagram showing color coordinates of colordisplay by the liquid crystal display;

FIG. 14 is a plan view illustrating the positional relation between thetransparent electrodes on the first substrate and the components formedon the second substrate, in a liquid crystal display according to amodification of the present invention;

FIG. 15 is a diagram illustrating an example of a liquid crystal displayaccording to the present invention, and is a partial cross-sectionalview illustrating an example of a passive matrix transflective colorliquid crystal display, wherein the color filter is provided on theinner side of the lower substrate;

FIG. 16 is a diagram illustrating only the transflective layer, colorfilter and shielding film of the liquid crystal display shown in FIG.15;

FIG. 16(A) is a plan view for describing the overlapping of thetransflective layer and the color filter;

FIG. 16(B) is a cross-sectional view along A-A′ shown in FIG. 16(A);

FIG. 17 is a diagram illustrating only the transflective layer and thecolor filter and the transparent electrodes on the lower substrate inthe liquid crystal display according to the fifth embodiment;

FIG. 17(A) is a plan view for describing the overlapping of thetransflective layer and the color filter;

FIG. 17(B) is a cross-sectional view along line C-C′ shown in FIG.17(A);

FIG. 18 is a diagram illustrating another example of a liquid crystaldisplay according to the present invention, and is a partialcross-sectional view illustrating an example of a passive matrixtransflective color liquid crystal display, wherein the color filter isprovided on the inner side of the upper substrate;

FIG. 19 is a diagram illustrating only the transflective layer and colorfilter of the liquid crystal display shown in FIG. 18;

FIG. 19(A) is a plan view for describing the overlapping of thetransflective layer and the color filter;

FIG. 19(B) is a cross-sectional view along B-B′ shown in FIG. 19(A);

FIG. 20 is a diagram illustrating further another example of a liquidcrystal display according to the present invention, and is a partialcross-sectional view illustrating an example of a passive matrixtransflective color liquid crystal display wherein transparentelectrodes are directly provided on the transflective layer;

FIG. 21 is a diagram illustrating only the transflective layer and colorfilter and transparent electrodes on the lower substrate, in the liquidcrystal display shown in FIG. 20;

FIG. 21(A) is a plan view for describing the overlapping of thetransflective layer and the color filter;

FIG. 21(B) is a cross-sectional view along line D-D′ shown in FIG.21(A);

FIG. 22 is a perspective view illustrating an example of a cellulartelephone;

FIG. 23 is a perspective view illustrating an example of a wristwatch-type electronic device;

FIG. 24 is a perspective view illustrating an example of a mobileinformation processing device, such as a word processor or a personalcomputer;

FIG. 25 is a diagram illustrating only the transflective layer and colorfilter and transparent electrodes on the lower substrate of the liquidcrystal display according to the test example 2;

FIG. 25(A) is a plan view for describing the overlapping of thetransflective layer and the color filter;

FIG. 25(B) is a cross-sectional view of FIG. 25(A);

FIG. 26 is a diagram illustrating only the transflective layer and colorfilter and transparent electrodes on the lower substrate of the liquidcrystal display according to the test example 3;

FIG. 26(A) is a plan view for describing the overlapping of thetransflective layer and the color filter;

FIG. 26(B) is a cross-sectional view of FIG. 26(A);

FIG. 27 is a diagram illustrating the results of measuring the lightemitted from the liquid crystal display according to the test example 1;

FIG. 27(A) is a chromaticity diagram of the light obtained in thereflective mode;

FIG. 27(B) is a chromaticity diagram of the light obtained in thetransmissive mode;

FIG. 28 is a diagram illustrating the results of measuring the lightemitted from the liquid crystal display according to the test example 2;

FIG. 28(A) is a chromaticity diagram of the light obtained in thereflective mode;

FIG. 28(B) is a chromaticity diagram of the light obtained in thetransmissive mode;

FIG. 29 is a diagram illustrating the results of measuring the lightemitted from the liquid crystal display according to the test example 3;

FIG. 29(A) is a chromaticity diagram of the light obtained in thereflective mode;

FIG. 29(B) is a chromaticity diagram of the light obtained in thetransmissive mode;

FIG. 30 is a diagram illustrating the results of measuring the lightemitted from the liquid crystal display according to the test example 4;

FIG. 30(A) is a chromaticity diagram of the light obtained in thereflective mode;

FIG. 30(B) is a chromaticity diagram of the light obtained in thetransmissive mode;

FIG. 31 is a diagram illustrating the spectral properties of the colorfilter used in the liquid crystal display according to the test example4, and is a graph illustrating the relation between the transmittance ofthe color filter and the wavelengths;

FIG. 32 is a diagram illustrating the transflective layer and colorfilter in the liquid crystal display according to an eighth embodiment;and

FIG. 33 is a diagram illustrating the transflective layer and colorfilter in the liquid crystal display according to a ninth embodiment.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The embodiments of the present invention will be described as followswith reference to the drawings. It should be understood that theembodiments illustrate one form of the present invention, but do notlimit the invention, and modifications may be made without departingfrom the spirit and the scope of the present invention.

First, the first embodiment, wherein the present invention is applied toa passive matrix transflective liquid crystal display, will be describedwith reference to FIG. 1. Note that in FIG. 1 and the subsequentdrawings, the scale of the layers and members differ one from another,in order to make the layers and members of a recognizable size in thedrawings.

As shown in FIG. 1, this liquid crystal display has a liquid crystaldisplay panel (liquid crystal panel) 500 including a first substrate(upper substrate) 3 and a second substrate (lower substrate) 2 attachedto each other with a seal member 503, and liquid crystals (a liquidcrystal layer) 4 sandwiched therebetween, and has an illumination device(a so-called back-light unit) 5 disposed at the second substrate 2 sideof the liquid crystal display panel 500. Also note that in the followingdescription, the opposite side of the liquid crystal display panel 500in relation to the illumination device 5 as shown in FIG. 1 will bereferred to as the “observation side”. That is to say, the “observationside” is the side at which an observer viewing images displayed on theliquid crystal display is situated.

The illumination device 5 can include a plurality of LEDs 621 (only oneis shown in FIG. 1) and a light guide plate 622. The plurality of LEDs621 are arrayed facing the side edge face of the light guide plate 622,and cast light onto this side edge face. The light guide plate 622 is aplate-shaped member for guiding light from the LEDs 621 incident on theside edge face to the substrate face of the liquid crystal display panel500 (the surface of the second substrate 2) in a uniform manner. Also, ascattering plate or the like is attached to the face of the light guideplate 622 facing the liquid crystal display panel 500 so as to scatterthe light emitted from the light guide plate 622 with respect to theliquid crystal display panel 500 in a uniform manner, while a reflectoris attached to the opposite face of the light guide plate 622 so as toreflect light heading from the light guiding plate 622 in the directionopposite from the liquid crystal display panel 500, toward the liquidcrystal display panel 500 (both omitted in the drawings).

Now, FIG. 2 is a graph illustrating an example of spectral properties ofthe illumination light (the relation of the wavelength and luminance ofthe illumination light) cast onto the liquid crystal display panel 500from the illumination device 5.

That is, in the graph in FIG. 2, the horizontal axis shows thewavelength, and the vertical axis shows the luminance of theillumination light at each of the wavelengths, as a relative valuewherein a predetermined luminance is set as “1.00” as a reference value.As shown in this drawing, in the present embodiment, a case is assumedwherein there are irregularities in the luminance in the illuminationlight over the wavelengths within the visible light range, i.e., whereinthe spectral properties of the illumination light are not uniform.Specifically, while the luminance of the illumination light according tothe present embodiment is greatest at a wavelength close to 470 nm whichcorresponds to blue through green light, the luminance at aroundwavelengths 520 nm or above corresponding to yellow light through redlight is comparatively weaker. Though the details will be described ingreater detail below, according to the liquid crystal display of thepresent embodiment, even in cases of performing transmissive displayusing illumination light with such irregularities in spectralproperties, the influence of the irregularities in the spectralproperties in the light emitted towards the observation side from theliquid crystal display panel 500 (i.e., the light viewed by theobserver, and hereafter referred to as “observation light”) issuppressed, and good color reproduction can be realized. Note that withthe present embodiment, a case is assumed wherein illumination lightwith the spectral properties shown in FIG. 2 is cast onto the entiresubstrate face of the liquid crystal display panel 500.

Returning to FIG. 1, the first substrate 3 and the second substrate 2 ofthe liquid crystal display panel 500 are plate-shaped transmissivemembers, such as glass or quartz, plastic, etc.

A plurality of transparent electrodes 511 are formed on the innersurface (the liquid crystals 4 side) of the first substrate 3. Thetransparent electrodes 511 are band-shaped electrodes extending in apredetermined direction (the left and right directions in FIG. 1), andare formed of a transparent conductive material such as ITO (Indium TinOxide) or the like. Further, the surface of the first substrate 3 wherethe transparent electrodes 511 are formed is covered by an alignmentlayer 15. This alignment layer 15 is an organic thin film, such aspolyimide or the like, and has been subjected to rubbing processing forstipulating the orientation of the liquid crystals 4 when voltage is notapplied.

Also, on the outer side of the first substrate 3 (the surface of theouter side), a retardation film 17 and an upper polarizer 13 are layeredand disposed in that order.

On the other hand, a reflective layer (transflective layer) 521 having aplurality of opening portions 521 a (described in detail later) isdisposed on the inner (liquid crystal 4 side) surface of the secondsubstrate 2 and formed of a material with light reflecting property,such as aluminum or silver for example. The incidental light from theobservation side of the liquid crystal display panel 500 is reflected atthe surface of this transflective layer 521 (more specifically, at thesurface other than the area where the opening portions 521 a are formed)and is emitted towards the observation side, thereby realizing areflective display. Now, the inner surface of the second substrate 2 ismade to be coarse so as to form a scattering structure (unevenness) atthe surface of the transflective layer 521, but this is omitted in thefigures.

Also, a ¼ wavelength plate 18 and a lower polarizer 14 are disposed onthe outer side (the surface of the outer side) of the second substrate2.

Further, formed on the inner side surface of the second substrate 2covered by the transflective layer 521 are a color filter 522 (522R,522G, 522B), a shielding layer 523, an overcoat layer (smoothing layer)524 for smoothing the unevenness formed by the color filter 522 and theshielding layer 523, a plurality of transparent electrodes 525, and analignment layer 9 the same as the above-described alignment layer 15.

The transparent electrodes 525 are band-shaped electrodes formed of atransparent conductive material on the surface of the overcoat layer524. Now, FIG. 3 schematically shows the positional relation between thetransparent electrodes 511 (shown by single-dot broken lines), on thefirst substrate 3, the transparent electrodes 525 on the secondsubstrate 2, and the color filter 522. As shown in the figure, thetransparent electrodes 525 extend in a direction intersecting thetransparent electrodes 511 (vertical to the paper in FIG. 1). The liquidcrystals 4 sandwiched between the first substrate 3 and the secondsubstrate 2 change in orientation thereof in response to voltage beingapplied between the transparent electrodes 511 and the transparentelectrodes 525. In the following description, areas where thetransparent electrodes 511 and the transparent electrodes 525 face oneanother as shown in FIG. 3 will be referred to as “sub-pixels 551 (551R, 551 G, 551 B)”. In other words, the sub-pixels 551 can also bedescribed as the smallest units of areas wherein the orientation ofliquid crystal changes according to application of voltage.

The shielding layer 523 is formed in a lattice-like shape so as to coverthe gap portions between the sub-pixels 551 arrayed in matrix fashion(that is to say, areas other than the areas where the transparentelectrodes 511 and the transparent electrodes 525 face one another),serving to shield from light the gaps between the sub-pixels 551. Thecolor filter 522 is a layer formed of a resin material or the likecorresponding to the sub-pixels 551, and as shown in FIG. 3, is colored,with a dye or pigment, either R (red), G (green), or B (blue). In thefollowing, sub-pixels corresponding to the color filters 522R, 522G, and522B, will respectively be referred to as sub-pixels 551R, 551G, and551B. These three sub-pixels 551R, 551G, and 551B with mutuallydiffering colors form a pixel (dot) 615, which is the smallest unit ofthe display image.

Now, FIG. 4 is a graph representing the transmittance properties of eachof the color filters 522R, 522G, and 522B, with the horizontal axis asthe wavelength of light incident on the color filter 522, and thevertical axis as transmittance (the percentage of light emitted as tothe amount of incident light). As shown in the figure, the color filter522R exhibits high transmittance for light with a wavelength 600 nm ormore which corresponds to red, the color filter 522G exhibits hightransmittance for light with a wavelength of 500 through 600 nm whichcorresponds to green, and the color filter 522B exhibits hightransmittance for light with a wavelength of 400 through 500 nm whichcorresponds to blue light.

Next, description will be made regarding the form of the openingportions 521 a formed in the transflective layer 521 a gain withreference to FIG. 3.

First, the opening portions 521 a are provided near the center of eachof the sub-pixels 551 on the transflective layer 521. Illumination lightform the illumination device 5 passes through the opening portions 521 aand is emitted towards the observation side of the liquid crystaldisplay panel 500, thereby realizing transmissive display. In thefollowing description, of the area of the sub-pixels 551, the areacorresponding to the opening portions 521 a, i.e., the area throughwhich illumination light from the illumination device 5 passes, will bereferred to as “light-transmitting area (transmissive area)”.

Further, the opening portions 521 a formed on the transflective layer521 have the dimension thereof selected such that the dimension of thelight-transmitting areas differs for each of the three sub-pixels 551R,551G, and 551B, making up each pixel 615. More specifically, thedimension of the opening portions 521 a corresponding to each of thesub-pixels 551R, 551G, and 551B corresponds to the spectral propertiesof the illumination light emitted from the illumination device 5.

With the present embodiment, as shown in FIG. 2, of the illuminationlight emitted from the illumination device 5, the luminance of thewavelengths from blue light to green light is relatively great, whilethe luminance of the wavelength corresponding to red light is relativelysmall. Accordingly, with regard to the sub-pixels 551G where the greencolor filter 522G corresponding to the wavelength with the greatestluminance is formed, the dimension of the opening portion 521 acorresponding thereto is formed smaller in comparison to the sub-pixels551R and 551B corresponding to the other colors. Conversely, with regardto the sub-pixels 551R where the red color filter 522R corresponding tothe wavelength with the least luminance of the illumination light is,the dimension of the opening portion 521 a corresponding thereto isformed larger in comparison to the sub-pixels 551G and 551Bcorresponding to the other colors. FIG. 3 shows an arrangement whereinthe dimension ratio of the opening portions 521 a corresponding to therespective sub-pixels 551R, 551G, and 551B is set at “sub-pixel551R:551G:551B=4:1:2”.

Now, FIG. 5 is a graph illustrating the spectral properties of theobserved light emitting to the observation side from the liquid crystaldisplay panel 500 in the event that transmissive display is carried outwith the above-described configuration. On the other hand, FIG. 6illustrates the spectral properties of the observed light in the eventthat transmissive display is carried out with an arrangement wherein alllight-transmitting areas are of the same dimension for all sub-pixels551 (hereafter referred to as “conventional configuration”), as acomparative example with that shown in FIG. 5. In either drawing, thespectral properties of the observed light in the event that transmissivedisplay is carried out using the illumination light with the spectralproperties shown in FIG. 2, is shown. In both FIG. 5 and FIG. 6, thehorizontal axis shows the wavelength, and the vertical axis shows theluminance of each of the observed light as a relative value withreference to a predetermined luminance (the same luminance in both FIG.5 and FIG. 6) set as a reference value “1.00”.

As shown in FIG. 6, in the event that the conventional configuration isemployed, the observed light visually recognized by the observer islight which has an extremely high luminance near the wavelength 470 nm.Accordingly, the image light visually recognized by the observer will bea blue-greenish image. Conversely, with the configuration according tothe present embodiment wherein the ratio of the light-transmitting areasin the sub-pixels 551R, 551G, and 551B is 4:1:2, the luminance in theobserved light near the wavelength 470 nm is comparatively lower thanthat in the case shown in FIG. 6, as shown in FIG. 5. Accordingly, asituation wherein that the image light visually recognized by theobserver is a blue-greenish image can be avoided even in the event thattransmissive display is carried out using illumination light wherein theluminance at wavelengths corresponding to blue through green colors isgreater than the luminance at other wavelengths.

Thus, with the configuration according to the present embodiment, of theillumination light, light at wavelengths with relatively small luminanceis allowed to sufficiently pass through the transflective layer 521,while light at wavelengths with relatively great luminance is restrictedto pass through the transflective layer 521, thereby suppressing theinfluence that irregularities in the spectral properties of theillumination light have on the observed light.

That is to say, the non-uniformity in the spectral properties of theillumination light is compensated, so that good color reproduction canbe realized.

Next, the second embodiment, wherein the present invention is applied toan active matrix transflective liquid crystal display, will bedescribed. Note that the following description illustrates a case usingTFDs (Thin Film Diode) which are two-terminal switching devices asswitching devices. Also, of the components in the figures describedbelow, the components which are in common with the components shown inFIG. 1 are given with the same reference numerals as in FIG. 1, anddescription thereof will be omitted.

First, FIG. 7 is a cross-sectional view schematically showing an exampleof the configuration of the liquid crystal display according to thepresent embodiment, and FIG. 8 is a perspective diagram illustrating theconfiguration of the principal components of the liquid crystal displaypanel making up the liquid crystal display. The cross-section along A-A′in FIG. 8 is equivalent to FIG. 7. As shown in these figures, aplurality of pixel electrodes 513 arrayed in matrix fashion, and aplurality of scanning lines 514 extending in a predetermined direction(the direction vertical to the paper in FIG. 7) in the gap portions ofthe pixel electrodes 513, are formed on the inner side surface of thefirst substrate 3. Each of the pixel electrodes 513 is formed of atransparent conductive material, such as ITO or the like, for example.Further, each of the pixel electrodes 513 and the scanning lines 514adjacent to the pixel electrodes 513 are connected by TFDs 515. Each ofthe TFDs 515 is a two-terminal switching device with a non-linearcurrent/voltage property.

On the other hand, as with the liquid crystal display according to thefirst embodiment above, formed on the inner side surface of the secondsubstrate 2 are a transflective layer 521 including a plurality ofopening portions 521 a, a color filter 522, a shielding layer 523, andan overcoat layer 524 for covering the surface of the second substrate 2where these are formed. Further, a plurality of data lines 527 extendingin a direction intersecting with the scanning lines 514 are formed onthe surface of the overcoat layer 524. As shown in FIGS. 7 and 8, thedata lines 527 are band-shaped electrodes formed of an transparentconductive material.

FIG. 9 shows the positional relation between the pixel electrodes 513(shown by single-dot broken lines) and the data lines 527. As shown inthe figure, the data lines 527 face the plurality of pixel electrodes513 arrayed in rows on the first substrate 3. With this configuration,the liquid crystals 4 sandwiched between the electrodes change inorientation state in response to voltage being applied between the pixelelectrodes 513 on the first substrate 3 and the data lines 527 on thesecond substrate 2. In other words, with the present embodiment, theareas where the pixel electrodes 513 and the data lines 527 face oneanother are equivalent to the sub-pixels 551 (more specifically,sub-pixels 551R, 551G, and 551B, corresponding to the respective colorfilters 522R, 522G, and 522B).

As with the above-described first embodiment, opening portions 521 a areformed at positions corresponding to the vicinity of the center portionof each of the sub-pixels 551 on the transflective layer 521 inaccordance with the present embodiment as well, as shown in FIG. 9. Thedimension of each of the opening portions 521 a is determined such thatthe percentage of the transmissive area in each of the sub-pixels 551R,551G, and 551B, is a percentage corresponding to the spectral propertiesof the illumination light from the illumination device 5. Now, thepresent embodiment also assumes performing transmissive display usingthe illumination light with the spectral properties shown in FIG. 2referred to above. Accordingly, at the sub-pixel 551G where the greencolor filter 522G corresponding to the wavelength which has the greatestluminance of the illumination light, the dimension of the openingportion 521 a corresponding thereto is smaller in comparison to thedimension of the opening portions 521 a corresponding to the sub-pixels551R or 551B corresponding to the other colors.

That is, the percentage of the light-transmitting area in the sub-pixel551G is smaller than the percentage of the light-transmitting areas inthe sub-pixels 551R or 551B of the other colors. Conversely, at thesub-pixel 551R corresponding to the wavelength which has the smallestluminance of the illumination light, the dimension of the openingportion 521 a corresponding thereto is greater and the percentage oflight-transmitting area in the sub-pixel 551R is greater in comparisonto that of the sub-pixels 551G or 551B of the other colors. In theexample shown in FIG. 9, a case is illustrated wherein the dimensionratio of the opening portions 521 a in the sub-pixels 551R, 551G, and551B, is “4:1:2”.

The same advantages as those of the first embodiment can be obtained bythis configuration, as well.

In the first and second embodiments, examples of a configuration whereinopening portions 521 a are provided near the center of areascorresponding to the sub-pixels 551 of the transflective layer 521, withthe light-transmitting area being positioned at the center of thesub-pixels 551, has been shown. Conversely, in accordance with thepresent embodiment, the transmissive areas are areas along the edges ofthe sub-pixels 551.

FIG. 10 is a cross-section diagram illustrating the configuration of theliquid crystal display according to the present embodiment. Note thatthe components shown in FIG. 10 that are in common with the componentsin FIG. 1 shown above are denoted by the same reference numerals. Asshown in the figure, the liquid crystal panel 500 according to thepresent embodiment differs from the liquid crystal panel 500 describedin the above embodiments in that the color filter 522 (522R, 522G,522B), a shielding layer 523, and a overcoat layer 524 are formed on thefirst substrate 3, and in that the transparent electrodes 511 andalignment layer 15 are formed on the surface of the overcoat layer.Further, the transmittance properties of the color filter 522 accordingto the present embodiment differs from the transmittance properties ofthe color filter 522 according to the above-described embodiments shownin FIG. 4.

Now, FIG. 11 is a graph illustrating the transmittance properties of thecolor filters 522R, 522G, and 522B, according to the present embodiment.As can be understood by comparing this drawing with the above-describedFIG. 4, the color purity of the color filters 522 according to thepresent embodiment, and particularly the color purity of the colorfilter 522G corresponding to the green color is higher than the colorpurity of the color filters 522 according to the above-describedembodiments. More specifically, this is explained as follows.

Now, taking into account a numerical value Tmax/Tmin, wherein Tmaxrepresents the maximum transmittance of each of the color filters 522 inthe wavelength range of 380 nm through 780 nm and Tmin represents theminimum transmittance in the same wavelength range, as a parameter forevaluating color purity (that is to say, the greater the numerical valueTmax/Tmin is, the higher the color purity is). At this time, while thenumerical value Tmax/Tmin of the green color filter 522G shown in theabove-described FIG. 4 is “1.8”, the numerical value Tmax/Tmin of thecolor filter 522G according to the present embodiment is “8”, andaccordingly it can be understood that the color purity of the colorfilter 522G according to the present embodiment is markedly higher thanthe color purity of the color filter 522G according to theabove-described embodiments.

Also, in accordance with the present embodiment, the form of thetransflective layer 528 differs from that of the first and secondembodiments. That is, in the above-described embodiments, examples ofconfiguration were described wherein the form of the transflective layer521 (more specifically, the form of the opening portions 521 a in thetransflective layer 521) is selected such that the areas positioned atthe center of the sub-pixels 551 serve as the light-transmitting areas.Conversely, with the present embodiment, the form of the transflectivelayer 528 is selected such that the areas along two opposing sides ofthe four sides defining each sub-pixel 551 that is substantiallyrectangular (the two sides extending in the Y direction) are made to bethe light-transmitting areas. The following is a description of thespecific form of the transflective layer 528, with reference to FIG. 12.

As shown in FIG. 12, the transflective layer 528 according to thepresent embodiment has a plurality of portions extending in the Ydirection on the second substrate 2. On the other hand, the transparentelectrodes 525 are of the same form as that shown in the above-describedembodiments, but differ in that they are formed so as to cover thetransflective layer 528. Thus, the transflective layer 528 according tothe present embodiment is formed in stripes so as to correspond to thetransparent electrodes 525. In other words, it can be said thattransmissive portions (portions for transmitting illumination light fromthe illumination device) 528 a are formed along the gap portions of thetransparent electrodes 525 on the transflective layer 528. As a resultof transmissive portions 528 a thus formed on the transflective layer528, the areas along the opposing sides extending in the Y direction, ofthe four sides defining the perimeter of the generally rectangularsub-pixel 551, serve as light-transmitting areas, as shown in FIG. 12.

In accordance with the present embodiment as well, the form of thetransflective layer 528 is selected such that the dimension of thelight-transmitting area at least in one sub-pixel 551 differs from thedimension of the light-transmitting areas in the other sub-pixels 551,as with the above-described first and second embodiments.

More specifically, as shown in FIG. 12, a width Wr of a reflective layercorresponding to a row of sub-pixels 551R and a width Wb of a reflectivelayer corresponding to a row of sub-pixels 551B are approximately equal,and a width Wb of a reflective layer corresponding to a row ofsub-pixels 551 G is wider than the width Wr and the width Wb.Accordingly, the dimension Sr of the light-transmitting area in thesub-pixel 551R and the dimension Sb of the light-transmitting area inthe sub-pixel 551B are approximately equal, while the dimension Sg ofthe light transmitting area in the sub-pixel 551G is smaller than thedimension Sr or dimension Sb.

Here, a case where the ratio of dimension Sr and dimension Sg anddimension Sb is “Sr:Sg:Sb=1.5:1:1.5” is assumed.

Now, as shown in FIG. 4, the transmittance of the green color filter522G shown in the above embodiment is markedly higher relative to thetransmittance of the other color filters 522R or 522 b of the othercolors. Accordingly, in order to perform ideal white display by usingthe color filter 522 with the transmittance properties shown in FIG. 4(i.e., color reproduction compensation), it is required to make thedimension of the light-transmitting area in the green sub-pixel 551Gmarkedly smaller than the dimension of the light-transmitting area inthe other color sub-pixels 551R or 551B. The transmittance of the colorfilter 522G with the transmittance properties shown in FIG. 11 issuppressed to a lower transmittance than the color filter 522G shown inFIG. 4, so that the difference between the dimension of thelight-transmitting area in the green sub-pixel 551G and the dimension ofthe light-transmitting area in the other color sub-pixels 551R or 551Bdoes not need to be secured at as high a level as in the case of usingthe color filter 522 shown in FIG. 4. That is to say, using the colorfilter 522G with the transmittance properties shown in FIG. 11 does awaywith the need for making the dimension of the light-transmitting area inthe green sub-pixel 551G all that smaller.

FIG. 13 is a CIE chromaticity diagram indicating color coordinates ofcolors displayed by the liquid crystal display according to the presentembodiment. In FIG. 13, the color coordinates of colors displayed by aliquid crystal display of a conventional configuration are shown as acomparative example with the present embodiment. Note that a“conventional configuration” of a liquid crystal display employs a colorfilter with the transmittance properties shown in FIG. 13 and has thesame dimension for the transmissive areas for all sub-pixels.

In the CIE chromaticity diagram, the color coordinate in the event ofperforming ideal white display is generally (x, y)=(0.310, 0.316), withthis point being indicated in FIG. 13 by an “x”. As can be clearly seenfrom the figure, the color coordinates in the case of performing whitedisplay with the liquid crystal display according to the presentembodiment are closer to the color coordinates of the ideal whitedisplay as compared to the color coordinates in the case of performingwhite display with the liquid crystal display according to theconventional configuration. In other words, good color reproduction canbe realized with the liquid crystal display according to the presentembodiment.

The advantages of suppressing the effects which irregularities in thespectral properties of the illumination light may have on the observedlight and realizing good color reproduction are obtained with thepresent embodiment as with the above-described embodiments.

As indicated in the present embodiment and the above-describedembodiments, in accordance with the present invention, as long as thepercentage of the light-transmitting area in one of the sub-pixelsmaking up a pixel and the percentage of the light-transmitting area inthe other sub-pixels making up the pixel differ, the form of thelight-transmitting areas of the sub-pixels, i.e., the form of thetransmissive portion (opening portion 521 a or transmissive portion 528a) in the transflective layer 521 may be any form. Also, the term“transmissive portion” in the present invention can mean “a portion inthe transflective layer through which illumination light from theillumination device is transmitted”, and is not restricted to openingportions (i.e., holes) formed in the transflective layer.

The above has been a description of an embodiment of the presentinvention, but the above-described embodiment is only an example, and itshould be understood that various modifications may be made to the aboveembodiment without departing from the spirit and scope of the presentinvention. Modifications such as given below may be made, for example.

In the above first and second embodiments, the arrangement is such thatthe dimension of the opening portions 521 a corresponding to thesub-pixels 551 is made to differ according to the spectral properties ofthe illumination light from the illumination device 5, but thearrangement may be as follows. That is, as shown in FIG. 14, thedimension of the opening portions 521 a provided in the transflectivelayer 521 are generally the same, while on the other hand, the number ofopening portions 521 a provided for each sub-pixel 551 is of a numberaccording to the spectral properties of the illumination light.

For example, in the above-described embodiments, the dimension ratio ofthe opening portions 521 a corresponding to the sub-pixels 551R, 551G,and 551B, is “4:1:2” to correspond to the spectral properties of theillumination light above illustrated in FIG. 2, but with the presentmodification, the ratio of the number of the opening portions 521 acorresponding to the sub-pixels 551R, 551G, and 551B, is made to be“4:1:2”, as shown in FIG. 4. The same advantages as those of the aboveembodiments can be obtained with this configuration as well. Also, asshown in the embodiments, while it is conceivable that graininess mightoccur in the image visually recognized by an observer as the results ofdeviation in the position of the opening portions 521 a in thesub-pixels 615, in the event that the opening portions 521 a are formedcorresponding to only a part of the sub-pixels 551. However, accordingto the configuration illustrated by the present modification, theopening portions 521 a can be scattered throughout the sub-pixels 551,and thus it is advantageous that such problems can be avoided.

In the above embodiments, the percentage of light-transmitting area inthe sub-pixels 551 is made to differ for each of the sub-pixels 551corresponding to the same color. Irregularities in the spectralproperties of the illumination light can be sufficiently compensatedwith this configuration in the event that the spectral properties of theillumination light from the illumination device 5 are the same throughthe entire substrate surface of the liquid crystal display panel 500.However, there may be cases wherein the spectral properties of theillumination light from the illumination device 5 differ according toplaces in the substrate face. For example, some places in the substrateface may be irradiated with illumination light with the spectralproperties shown in FIG. 2, while other places may be irradiated withillumination light with spectral properties other than those shown inFIG. 2.

In such cases, the percentage of the light-transmitting area may bechanged according to the position of the sub-pixels 551 in the substrateface (i.e., dimension of the opening portions 521 a may be made todiffer). For example, while the dimension ratio of thelight-transmitting area in the sub-pixels 551R, 551G, and 551B, may be“4:1:2” at a pixel 615 situated at a position wherein illumination lightwith the spectral properties illustrated in FIG. 2 is irradiated, thedimension ratio of the light-transmitting area in the sub-pixels 551R,551G, and 551B, may be “3:1:2” at a pixel 615 situated at a positionwherein illumination light with somewhat less luminance in the bluelight through the green light as compared to the above illuminationlight is irradiated. In this way, there is no particular need for thepercentage of the light-transmitting area of the sub-pixels 551corresponding to the same color to be all the same throughout thesub-pixels 551. According to the present modification, in addition tothe advantages shown with the above embodiments, non-uniformity ofspectral properties of the illumination light in the substrate face canbe compensated, and thus an advantage that color reproduction can bemore reliably improved is obtained.

While the above embodiments illustrate examples wherein the illuminationlight from the illumination device exhibit the spectral propertiesillustrated in FIG. 2, it should be apparent that the spectralproperties of the illumination light are not restricted to these. Thatis, even in cases of using illumination light exhibiting spectralproperties other than those shown in FIG. 2 for transmissive display,advantages are obtained that irregularities in the spectral propertiesof the illumination light can be compensated and good color reproductioncan be realized, by setting the dimension according to the spectralproperties of the illumination light, such as making the dimension ofthe light-transmitting area in sub-pixels of a color corresponding to awavelength of the illumination light with great luminance be smallerthan the dimension of the light-transmitting area in sub-pixels of acolor corresponding to a wavelength with less luminance.

Moreover, the dimension of the light-transmitting area of the sub-pixelsdoes not necessarily need to correspond to the spectral properties ofthe illumination light. For example, when the dimension of thelight-transmitting area in the sub-pixels 551G corresponding to green orthe dimension of the light-transmitting area in the sub-pixels 551Bcorresponding to blue (i.e., the dimension of the opening portions 521 acorresponding to these sub-pixels 551) is arranged to be greater thanthe dimension of the light-transmitting area in the sub-pixels 551Rcorresponding to red regardless of the spectral properties of theillumination light, it is possible for the display to be intentionallymade blue-greenish. That is, in accordance with the present invention,all that is necessary is for the dimension of the opening portion 521 ain the transflective layer 521 to be set such that the dimension of thelight-transmitting area for one sub-pixel 551 is different from thedimension of the light-transmitting area for another sub-pixel 551.

In the above third embodiment, a case is illustrated wherein the form ofthe transflective layer 528 is selected such that the areas along twoopposing sides of the four sides defining each sub-pixel are made to bethe light-transmitting areas, but the form of the transflective layer528 may be selected such that the area along one side, three sides, orall sides (four sides) of the four sides is used as thelight-transmitting area. In other words, in the case of setting the areaalong the edges of the sub-pixel to be the light-transmitting area, allthat is necessary is to make an area along at least one of the pluralityof sides defining the sub-pixels be the light-transmitting area. Also,in the third embodiment, a transflective layer 528 in a form of beingaligned over a plurality of sub-pixels 551 has been illustrated, but thetransflective layer 528 may be of a form separated for each sub-pixel551.

Though the above embodiments illustrate an example of a case of using astripe array, wherein the color filters 522 of the same color form arow, other forms of arraying the color filters 522, such as mosaicarrays or delta arrays, may be used.

Also, the above embodiments illustrate a case wherein the transflectivelayer 521 is formed on the inner surface of the second substrate 2, butan arrangement may be conceived wherein the transflective layer 521 isformed on the outer surface of the second substrate 2. In short, aconfiguration wherein the transflective layer 521 is situated at theopposite side of the liquid crystal 4 in relation to the observationside will suffice.

Though the above second embodiment describes an example of an activematrix liquid crystal display using TFDs 515 as the switching devices,it should be understood that the applicable scope of the presentinvention is not restricted to this, and can also be applied to liquidcrystal displays using three-terminal switching devices, of which TFTs(Thin Film Transistor) are representative. Note that in the case ofusing TFTs, a counter electrode can be formed on the entire face of onesubstrate, while a plurality of scanning lines and a plurality of datalines can be formed on the other substrate so as to extend in thedirections where they intersect each other, and pixel electrodesconnected to both of these via TFTs are arrayed in matrix fashion. Inthis case, the areas where the pixel electrodes and the counterelectrode face one another function as the sub-pixels.

Though the above embodiments illustrate a case wherein the transflectivelayer 521 and the transparent electrodes 525 (data lines 527 in thesecond embodiment) are formed separately, but an arrangement may be madewherein an electrode for applying voltage to the liquid crystal 4 isformed of a conductive material including light-reflecting properties,so that this electrode also functions as the transflective layer 521.That is, as shown in FIG. 1, the transflective layer 521 is notprovided, and a reflecting electrode of the same form as the transparentelectrode 525 is provided in place thereof. In this case, openingportions of the forms illustrated as examples in the above embodimentsand modifications are provided at a portion of the areas of thereflecting electrode corresponding to the sub-pixels (i.e., the areasfacing the transparent electrode 511 on the first substrate 30).

FIG. 15 is a diagram illustrating an example of the liquid crystaldisplay according to the present invention, and is a partialcross-sectional diagram illustrating an example of a passive matrixtransflective color liquid crystal display wherein a color filter isprovided on the inner side of the lower substrate. Also, FIG. 16 is adiagram illustrating only the transflective layer and color filter andshielding film of the liquid crystal display shown in FIG. 15, whereinFIG. 16(A) is a plan view for describing the overlapping of thetransflective layer and the color filter, and FIG. 16(B) is across-sectional view along A-A′ shown in FIG. 16(A).

Note that in the following drawings, the ratio of the film thickness anddimensions of the components are changed as appropriate to facilitateviewing of the drawings.

The liquid crystal display shown in FIG. 15 has a schematicconfiguration including a liquid crystal panel (liquid crystal displaypanel) 1, and a back-light (illumination device) disposed at the rearside of the liquid crystal panel 1 (at the outer side of the lowersubstrate 2).

Also, the liquid crystal panel 1 has a schematic configuration includinga liquid crystal layer 4 of STN (Super Twisted Nematic) liquid crystalsor the like sandwiched between the lower substrate 2 and upper substrate3 disposed facing one another.

The lower substrate 2 is formed of glass, resin or the like, with atransflective layer 6 disposed on the inner face side of the lowersubstrate 2, a color filter 10 layered on the upper side of thetransflective layer 6, and with a shielding film 41 of a black-coloredresin material or the like provided between the pigment layers 11R, 11G,and 11B making up the color filter 10. Also, a transparent smoothingfilm 12 for smoothing the unevenness formed by the color filter 10 islayered on the color filter 10. Further, stripe-shaped transparentelectrodes (segment electrodes) 8 formed of a transparentelectroconductive film such as indium tin oxide (hereafter referred toas “ITO”) or the like are extended in the vertical direction to thepaper on the smoothing film 12, and an alignment layer 9 of polyimide orthe like is disposed above the transparent electrodes 8 so as to coverthe transparent electrodes 8.

Also, a ¼ wavelength plate 18, a lower polarizer 14, and a reflectingpolarizer 19, are disposed on the outer side of the lower substrate 2.

On the other hand, the upper substrate 3 is formed of glass or resin orthe like, with stripe-shaped transparent electrode (common electrode) 7formed of a transparent conductive film such as ITO or the like on theinner side of the upper substrate 3, extending in the directionorthogonal to the transparent electrodes 8 provided on the lowersubstrate 2 (the sideways direction in the drawing), and with analignment layer 15 of polyimide or the like disposed below thetransparent electrode 7 so as to cover the transparent electrode 7.

Also, on the outer side of the upper substrate 3, a forward scatteringplate 16, a retardation film 17, and an upper polarizer 13 are layeredand disposed in that order on the upper substrate 3.

Also, a reflector 51 is disposed on the lower face side of theback-light 5 (the side opposite from the liquid crystal panel 1).

Next, the planar overlapping of the transflective layer 6 and the colorfilter 10 in the liquid crystal display shown in FIG. 15 will bedescribed. The transflective layer 6 is formed of a metal film with highreflectivity such as aluminum or the like, and as shown in FIG. 16, isformed by opening the metal film in the form of windows. Thetransflective layer 6 comprises, for each pixel, transmissive areas 6 afor transmitting light emitted from the back-light 5 and incident lightfrom the upper substrate 3 side, and a reflective area 6 b forreflecting incident light from the upper substrate 3 side.

On the other hand, the color filter 10 is provided corresponding to eachpixel making up the display area, having pigment layers repeatedlyarrayed in the order of the red layer 11R, the green layer 11G, and theblue layer 11B, with the red layer 11R, the green layer 11G and the bluelayer 11B extending in the direction vertical to the paper so as to beorthogonal to the transparent electrode 7 provided on the uppersubstrate 3 described above.

The pigment layers 11R, 11G, and 11B can be provided on the entirety ofthe area overlapping the transmissive areas 6 a of the transflectivelayer 6 in a planar manner, and an area excluding a part of an areaoverlapping the reflective area 6 b of the transflective layer 6 in aplanar manner with the pigment layers 11R, 11G, and 11B opened in windowfashion, as shown in FIG. 16. Thus, the color filter 10 includes apigment layer formation area wherein the pigment layers 11R, 11G, and11B are provided, and pigment layer non-formation areas 11D, 11E, and11F which are a part of an area overlapping with the reflective area 6 bin a planar manner and where the pigment layers 11R, 11G, and 11B arenot provided. Also, with this liquid crystal display, the dimension ofthe pigment layer formation area, i.e., the dimension of the pigmentlayers 11R, 11G, and 11B, is set to be smaller in the order of the redlayer 11R, blue layer 11B, and green layer 11G.

As shown in FIG. 15, with such a liquid crystal display, external light30 a cast into the liquid crystal display from the upper substrate 3side in the reflective mode passes through the color filter 10, isreflected by the reflective area 6 b of the transflective layer 6,passes through the color filter 10 again, and is emitted externally fromthe upper substrate 3 side. External light 30 b incident onto the liquidcrystal display from the upper substrate 3 side in the reflective modedoes not pass through the color filter 10 but is reflected by thereflective area 6 b, and is emitted externally from the upper substrate3 side. External light 30 c incident on the liquid crystal display fromthe upper substrate 3 side in the reflective mode passes through thetransmissive areas 6 a, and accordingly does not become reflected light.

In other words, as the reflected light, there are light 30 a whichpasses through the pigment layers 11R, 11G, and 11B, and light 30 bwhich passes through the pigment layer non-formation areas 11D, 11E, and11F, and only the light 30 a which has passed through the pigment layers11R, 11G, and 11B is colored, and the light 30 b which has passedthrough the pigment layer non-formation areas 11D, 11E, and 11F is notcolored.

Accordingly, the light emitted externally from the upper substrate 3side when in the reflective mode is the sum of the colored light 30 awhich has passed through the pigment layers 11R, 11G, and 11B and theuncolored light 30 b which has passed through the pigment layernon-formation areas 11D, 11E, and 11F.

Also, the light 50 a cast into the liquid crystal display from theback-light 5 when in the transmissive mode passes through thetransmissive areas 6 a, passes through the pigment layers 11 of thecolor filter 10, and is colored. Also, the light 50 b cast into theliquid crystal display from the back-light 5 when in the transmissivemode is shielded by the transflective layer 6.

Accordingly, the light emitted externally from the upper substrate 3side when in the transmissive mode becomes light 50 a which has passedthrough the pigment layers 11 of the color filter 10 once and iscolored.

With such a liquid crystal display, there are pigment layernon-formation areas 11D, 11E, and 11F at a part of an area overlappingwith the reflective area 6 b in a planar manner. Thus, as describedabove, the light obtained in the reflective mode is the sum of theuncolored light 30 b which has passed through the pigment layernon-formation areas 11D, 11E, and 11F and the colored light 30 a whichhas passed through the pigment layers 11. On the other hand, the lightobtained in the transmissive mode is only the light 50 a which passesthrough the pigment layer 11 and is colored.

Accordingly, the difference in color concentration between the lightpassing through the color filter 10 twice in the reflective mode and thelight passing through the color filter 10 once in the transmissive modecan be reduced. Consequently, a color transflective liquid crystaldisplay capable of a bright display with high visibility both in thereflective mode and transmissive mode, can be realized.

Moreover, with the liquid crystal display shown in FIG. 15, the pigmentlayer 11 is formed of the red layer 11R, the green layer 11G, and theblue layer 11B, with the dimension of the pigment layers 11R, 11G, and11B being smaller in the order of the red layer 11R, blue layer 11B, andgreen layer 11G. The color properties of the color filter 10 areadjusted by changing the dimension of the pigment layers 11R, 11G, and11B, so that the color reproduction can be improved even further, and aliquid crystal display with even more excellent display quality can berealized.

Also, the liquid crystal display shown in FIG. 15 has a transparent film12 for smoothing the steps between the areas where the pigment layers11R, 11G, and 11B are provided and the pigment layer non-formation areas11D, 11E, and 11F, so adverse effects due to steps between the areaswhere the pigment layers 11R, 11G, and 11B are provided and the pigmentlayer non-formation areas 11D, 11E, and 11F can be avoided, therebyimproving the reliability of the liquid crystal display.

Also, the transflective layer fabricated of a thin metal film absorbslight in addition to reflecting and transmitting light, but with theliquid crystal display shown in FIG. 15, the transflective layer 6 isopened in a window-like manner, thereby forming the transmissive areas 6a. Thus, there is no absorbing of light, thereby improving thereflectivity and transmittance.

With the fifth embodiment, the overall configuration of the liquidcrystal display is the same as the fourth embodiment shown in FIG. 15,and accordingly detailed description will be omitted.

Also, the difference between the liquid crystal display according to thefifth embodiment and the liquid crystal display according to the fourthembodiment is only the forms of the transflective layer and the colorfilter, and thus description of the transflective layer and the colorfilter will be given in detail with reference to FIG. 17.

FIG. 17 is a diagram illustrating only the transflective layer, thecolor filter, and the transparent electrodes on the lower substrate inthe liquid crystal display according to the fifth embodiment, whereinFIG. 17(A) is a plan view for describing the overlapping of thetransflective layer and the color filter, and FIG. 17(B) is across-sectional diagram along line C-C′ shown in FIG. 17(A).

Note that in FIG. 17, the components held in common with the fourthembodiment are denoted with the same reference numerals.

As with the transparent electrodes 8 provided on the lower substrate 2,the transflective layer 61 is extended and provided in a stripe form inthe direction vertical to the paper so as to be orthogonal to thetransparent electrode 7 provided on the upper substrate 3, and providedwith the same pitch as the transparent electrodes 8 provided on thelower substrate 2. Then, as shown in FIG. 17(B), the width of thepattern of the transparent electrodes 8 provided on the lower substrate2 is formed so as to be greater than the width of the metal film patternmaking up the transflective layer 61, so that band-shaped areas wherethe metal film making up the transflective layer 61 and the transparentelectrodes 8 do not overlap in a parallel manner serve as transmissiveareas 61 a, and the entire area where the metal film is provided servesas a reflective area 61 b.

On the other hand, as with the fourth embodiment, the color filter 101is provided for each of the pixels making up the display area, includingpigment layers 111 repeatedly arrayed in the order of the red layer111R, the green layer 111G, and the blue layer 111B, with the red layer111R and green layer 111G and blue layer 111B extending in the directionvertical to the paper so as to be orthogonal to the transparentelectrode 7 provided on the upper substrate 3.

As shown in FIG. 17, the pigment layers 111R, 111G, and 111B areprovided on the entirety of the area overlapping the transmissive areas61 a of the transflective layer 61 in a planar manner, and an areaexcluding a part of an area overlapping the reflective area 61 b of thetransflective layer 61 in a planar manner with the pigment layers 111R,111G, and 111B opened in stripe forms.

Accordingly, the color filter 101 includes a pigment layer formationarea where the pigment layers 111R, 111G, and 111B are formed, andpigment layer non-formation areas 111D, 111E, and 111F which are a partof an area overlapping with the reflective area 61 b in a planar mannerand where the pigment layers 111R, 111G, and 111B are not provided.

Also, with this liquid crystal display, the dimension of the pigmentformation area, i.e., the dimension of the pigment layers 111R, 111G,and 111B, is set so as to be smaller in the order of the red layer 111R,the blue layer 111B, and the green layer 111G, as with the fourthembodiment.

Such a liquid crystal display also has pigment layer non-formation areas111D, 111E, and 111F at a part of an area overlapping with thereflective area 61 b of the transflective layer 61 in a planar manner,as with the fourth embodiment, so that a part of the external lightincident on the liquid crystal display in the reflective mode passesthrough the pigment layer non-formation areas 111D, 111E, and 111F, andthe light passing through the color filter 101 twice in the reflectivemode is the sum of the uncolored light which has passed through thepigment layer non-formation areas 111D, 111E, and 111F and the coloredlight which has passed through the pigment layers 111. On the otherhand, the light which is incident from the back-light 5 in thetransmissive mode and passes through the transmissive areas 61 a allpasses through the pigment layer 111, so that light passing through thecolor filter 101 once in the transmissive mode is all colored.Accordingly, the difference in color concentration between the lightpassing through the color filter twice in the reflective mode and thelight passing through the color filter once in the transmissive mode canbe reduced.

Consequently, a color transflective liquid crystal display capable ofdisplay with good coloring and high visibility both in the reflectivemode and transmissive mode can be realized.

Moreover, with the liquid crystal display according to the presentembodiment as well, the pigment layer 111 is formed of the red layer111R, the green layer 111G, and the blue layer 111B, with the dimensionof the pigment layers 111R, 111G, and 111B being smaller in the order ofthe red layer 111R, the blue layer 111B, and the green layer 111G . Thecolor properties of the color filter 101 are adjusted by changing thedimension of the pigment layers 11R, 111G, and 111B, so that the colorreproduction can be improved even further, and a liquid crystal displaywith even more excellent display quality can be realized.

Also, in accordance with such a liquid crystal display, with regard tothe transflective layer 61, the width of the pattern of the transparentelectrodes 8 provided on the lower substrate 2 is formed so as to begreater than the width of the metal film pattern making up thetransflective layer 61, thereby forming band-shaped transmissive areas61 a and reflective areas 61 b are formed. Thus, irregularities in thelongitudinal direction of the openings are reduced as compared to atransflective layer with window-like openings, providing stability fromthe perspective of manufacturing.

FIG. 18 is a diagram illustrating an example of another liquid crystaldisplay according to the present invention, and is a partialcross-sectional view illustrating an example of a passive matrixtransflective color liquid crystal display wherein a color filter isprovided on the inner side of the upper substrate. Also, FIG. 19 is adiagram illustrating only the transflective layer and color filter ofthe liquid crystal display shown in FIG. 18, wherein FIG. 19(A) is aplan view for describing the overlapping of the transflective layer andthe color filter, and FIG. 19(B) is a cross-sectional view along B-B′shown in FIG. 19(A).

Note that in FIG. 18 and FIG. 19, the components held in common with thefourth embodiment are denoted with the same reference numerals, andaccordingly detailed description thereof will be omitted.

The liquid crystal display shown in FIG. 18 has a schematicconfiguration having a liquid crystal panel 100 and a back-light(illumination device) 5 disposed at the rear side of the liquid crystalpanel 100 (at the outer side of the lower substrate 2).

Also, the liquid crystal panel 100 has a schematic configurationincluding a liquid crystal layer 4 sandwiched between the lowersubstrate 2 and upper substrate 3 disposed facing one another, as withthe fourth embodiment.

The lower substrate 2 has on the inner side thereof a transflectivelayer 6 and an insulating film 23 in that order, with a stripe-shapedtransparent electrode 8 (a common electrode here) formed of atransparent conductive film such as ITO or the like extending sidewaysin the drawing upon the insulating film 23, and with an alignment layer9 disposed above the transparent electrode 8 so as to cover thetransparent electrode 8. Also, a ¼ wavelength plate 18, a lowerpolarizer 14, and a reflecting polarizer 19, are disposed on the outerside of the lower substrate 2, as with the fourth embodiment.

On the other hand, a color filter 20 is layered on the inner side of theupper substrate 3, with a shielding film 42 of a black-colored resinmaterial or the like provided between the pigment layers 21R, 21G, and21B making up the color filter 20. Also, a transparent smoothing film 22for smoothing the unevenness formed by the color filter 20 is layeredbelow the color filter 20. Further, stripe-shaped transparent electrodes(segment electrodes here) 7 formed of a transparent conductive film suchas ITO or the like are extended in a direction orthogonal to thetransparent electrode 8 disposed on the lower substrate 2 (in thevertical direction to the paper) under the smoothing film 22, and analignment layer 15 is disposed below the transparent electrodes 7 so asto cover the transparent electrodes 7.

Also, a forward scattering plate 16, a retardation film 17, and an upperpolarizer 13 are layered and disposed in that order on the outer side ofthe upper substrate 3, as with the fourth embodiment. Also, a reflector51 is disposed on the lower face side of the back-light 5 (the sideopposite from the liquid crystal panel 1), as with the fourthembodiment.

Next, the planar overlapping of the transflective layer and the colorfilter in the liquid crystal display shown in FIG. 18 will be described.With the liquid crystal display shown in FIG. 18, the position of theliquid crystal display according to the fourth embodiment shown in FIG.15 and the position of the color filter thereof are different, but theplanar overlapping of the transflective layer and the color filter isthe same as that in the fourth embodiment.

The transflective layer 6 is the same as that in the fourth embodimentand, as shown in FIG. 19, is formed by opening metal film in the form ofwindows, including, for each pixel, transmissive areas 6 a and areflective area 6 b.

On the other hand, the color filter 20 includes pigment layers 21repeatedly arrayed in the order of the red layer 21R, green layer 21G,and blue layer 21B, with the red layer 21R, the green layer 21G, and theblue layer 21B extending in the direction vertical to the paper so as tobe orthogonal to the transparent electrode 8 provided on the lowersubstrate 2.

As shown in FIG. 19, the pigment layers 21R, 21G, and 21B are providedon the entirety of the area overlapping the transmissive areas 6 a ofthe transflective layer 6 in a planar manner, and an area excluding apart of an area overlapping the reflective area 6 b of the transflectivelayer 6 in a planar manner with the pigment layers 21R, 21G, and 21Bopened in window fashion. Thus, the color filter 20 includes a pigmentlayer formation area wherein the pigment layers 21 are provided, andpigment layer non-formation areas 21D, 21E, and 21F which are a part ofan area overlapping with the reflective area 6 b in a planar manner andwhere the pigment layers 21R, 21G, and 21B are not provided. Also, withthis liquid crystal display, the dimension of the pigment formationarea, i.e., the dimension of the pigment layers 21R, 21G, and 21B, isset to be smaller in the order of the red layer 21R, the blue layer 21B,and the green layer 21G, as with the fourth embodiment.

As shown in FIG. 18, with such a liquid crystal display as well, as thelight which is emitted externally from the upper substrate 3 side in thereflective mode, there are light 30 a which passes through the pigmentlayers 21R, 21G, and 21B, and light 30 b which passes through thepigment layer non-formation areas 21D, 21E, and 21F, and only the light30 a which has passed through the pigment layers 21R, 21G, and 21B iscolored, and the light 30 b which has passed through the pigment layernon-formation areas 21D, 21E, and 21F is not colored. Accordingly, aswith the fourth embodiment, with such a liquid crystal display, thelight emitted externally from the upper substrate 3 side in thereflective mode is the sum of the uncolored light 30 b and the coloredlight 30 b.

On the other hand, the light externally emitted from the upper substrate3 side in the transmissive mode also becomes colored light 50 a whichhas passed through the pigment layers 21 of the color filter 20 once, aswith the fourth embodiment.

Accordingly, with the liquid crystal display according to the presentembodiment as well, the difference in color concentration between thelight passing through the color filter 20 twice in the reflective modeand the light passing through the color filter 20 once in thetransmissive mode can be reduced. Consequently, a color transflectiveliquid crystal display capable of display with good coloring and a highvisibility both in the reflective mode and transmissive mode can berealized.

Moreover, with the liquid crystal display shown in FIG. 19, the pigmentlayer 21 is formed of the red layer 21R, the green layer 21G, and theblue layer 21B, with the dimension of the pigment layers 21R, 21G, and21B being smaller in the order of the red layer 21R, the blue layer 21B,and the green layer 21G. The color properties of the color filter 20 areadjusted by changing the dimension of the pigment layers 21R, 21G, and21B, so that the color reproduction can be improved even further, and aliquid crystal display with even more excellent display quality can berealized.

FIG. 20 is a diagram illustrating an example of another liquid crystaldisplay according to the present invention, and is a partialcross-sectional view illustrating an example of a passive matrixtransflective liquid crystal display wherein transparent electrodes aredirectly provided on the transflective layer. Also, FIG. 21 is a diagramillustrating only the transflective layer, a color filter andtransparent electrodes on the lower substrate, in the liquid crystaldisplay shown in FIG. 20, wherein FIG. 21 (A) is a plan view fordescribing the overlapping of the transflective layer and the colorfilter, and FIG. 21(B) is a cross-sectional view along D-D′ shown inFIG. 21 (A).

Note that in FIG. 20 and FIG. 21, the components held in common with thefourth embodiment are denoted with the same reference numerals, andaccordingly, detailed description will be omitted.

The liquid crystal display shown in FIG. 20 has a schematicconfiguration having a liquid crystal panel 200 and a back-light(illumination device) 5 disposed at the rear side of the liquid crystalpanel 200 (at the outer side of the lower substrate 2). Also, the liquidcrystal panel 200 has a schematic configuration including a liquidcrystal layer 4 sandwiched between the lower substrate 2 and uppersubstrate 3 disposed facing one another, as with the fourth embodiment.

The lower substrate 2 includes on the inner side thereof a transflectivelayer 62 formed of a metal film with high light reflecting property suchas aluminum or the like, and stripe-shaped transparent electrodes 8(segment electrodes here) disposed directly on the transflective layer62 and formed of a transparent electroconductive film such as ITO or thelike, both extending vertically in the drawing, and an alignment layer 9disposed above the transparent electrodes 8 so as to cover thetransparent electrodes 8. Also, a ¼ wavelength plate 18, a lowerpolarizer 14, and a reflecting polarizer 19, are disposed on the outerside of the lower substrate 2, as with the fourth embodiment.

On the other hand, a color filter 104 is layered on the inner side ofthe upper substrate 3, with a shielding film 43 provided between thepigment layers 114R, 114G, and 114B making up the color filter 104.Also, a transparent smoothing film 32 for smoothing the unevennessformed by the color filter 104 is layered below the color filter 104.Further, a stripe-shaped transparent electrode (a common electrode here)7 formed of a transparent conductive film ITO or the like is extended ina direction orthogonal to the transparent electrodes 8 disposed on thelower substrate 2 (in the sideways direction to the paper) under thesmoothing film 32, and an alignment layer 15 is disposed below thetransparent electrode 7 so as to cover the transparent electrode 7.

Also, at the outer side of the upper substrate 3, a forward scatteringplate 16, a retardation film 17, and an upper polarizer 13 are layeredand disposed in that order, as with the fourth embodiment. Also, areflector 51 is disposed on the lower face side of the back-light 5 (theside opposite from the liquid crystal panel 1), as with the fourthembodiment.

Next, the planar overlapping of the transflective layer and the colorfilter in the liquid crystal display shown in FIG. 20 will be described.

The transflective layer 62, as with the fifth embodiment, is providedwith the same pitch as the transparent electrodes 8 provided on thelower substrate 2, and as shown in FIG. 21(B), the width of the patternof the transparent electrodes 8 provided on the lower substrate 2 isformed so as to be greater than the width of the metal film patternmaking up the transflective layer 62, so that band-shaped areas wherethe metal film making up the transflective layer 62 and the transparentelectrodes 8 do not overlap in a planar manner serve as transmissiveareas 62 a, and the entire area where the metal film is provided servesas a reflective area 62 b.

On the other hand, the color filter 104 is provided corresponding toeach of the pixels making up the display area as with the fourthembodiment, and includes pigment layers 114 repeatedly arrayed in theorder of the red layer 114R, the green layer 114G, and the blue layer114B, with the red layer 114R, green layer 114G, and blue layer 114Bextending in the direction vertical to the paper so as to be orthogonalto the transparent electrode 7 provided on the upper substrate 3.

As shown in FIG. 21, the green layer 114G is provided on the entirety ofthe area overlapping the transmissive areas 62 a of the transflectivelayer 62 in a planar manner, and an area excluding a part of an areaoverlapping the reflective area 62 b of the transflective layer 62 in aplanar manner with the green layer 114G opened in stripe fashion. Thus,the color filter 104 has a pigment layer formation area wherein thepigment layers 114R, 114G, and 114B are provided, and a pigment layernon-formation area 114E which is a part of an area overlapping with thereflective area 62 b in a planar manner and where the green layer 114Gis not provided. Also, with this liquid crystal display, the dimensionof the pigment formation area, i.e., the dimension of the pigment layers114R, 114G, and 114B, is set to be smaller in the order of the red layer114R, the blue layer 114B, and the green layer 114G.

As shown in FIG. 20, with such a liquid crystal display as well, as thelight which is emitted externally from the upper substrate 3 side in thereflective mode, there are light 30 a which passes through the pigmentlayers 114R, 114G, and 114B, and light 30 b which passes through thepigment layer non-formation area 114E, and only the light 30 a which haspassed through the pigment layers 114R, 114G, and 114B is colored, andthe light 30 b which has passed through the pigment layer non-formationarea 114E is not colored. Accordingly, with such a liquid crystaldisplay as well, the light emitted externally from the upper substrate 3side when in the reflective mode is the sum of the uncolored light 30 band the colored light 30 b, as with the forth embodiment.

On the other hand, the light externally emitted from the upper substrate3 side in the transmissive mode also becomes colored light 50 a whichhas passed through the pigment layers 114 of the color filter 104 once,as with the fourth embodiment.

Accordingly, with the liquid crystal display according to the presentembodiment as well, the difference in color concentration between thelight passing through the color filter 104 twice in the reflective modeand the light passing through the color filter 104 once in thetransmissive mode can be reduced. Consequently, a color transflectiveliquid crystal display capable of display with good coloring and a highvisibility both in the reflective mode and transmissive mode can berealized.

Moreover, with the liquid crystal display according to the presentembodiment, the pigment layer 114 is formed of the red layer 114R, thegreen layer 114G, and the blue layer 114B, with the dimension of thepigment layers 114R, 114G, and 114B being smaller for the green layer114G than for the red layer 114R and blue layer 114B, and the colorproperties of the color filter 104 are adjusted by changing thedimension of the green layer 114G, so that the color reproduction can beimproved even further, and a liquid crystal display with even moreexcellent display quality can be realized.

Further, the pigment layer non-formation area 114E is provided only tothe green layer 114G which contributes to colorization of green, whichis the most visually effective color, so that excellent colorization canbe obtained, and deterioration of reflectance due to providing thepigment layer non-formation area 114E can be reduced.

Further, with the liquid crystal display according to the presentembodiment, the transparent electrodes 8 formed of a transparentelectroconductive film are directly disposed on the transflective layer62 formed of a metal film, so that the resistance value of thetransparent electrodes 8 can be reduced, thereby reducing colorunevenness in display.

With the eighth embodiment, the overall configuration of the liquidcrystal display is the same as the fourth embodiment shown in FIG. 15,and accordingly detailed description will be omitted.

Also, the liquid crystal display according to the eighth embodiment hasdifferent area for the transmissive areas of the sub-pixels as with theabove-described first embodiment, and also is formed so that thedimensions of the pigment layer non-formation areas in the pigment layerdiffer as with the above-described fourth embodiment. Accordingly,detailed description of the configurations which are the same as theliquid crystal display according to the first embodiment and the liquidcrystal display according to the fourth embodiment will be omitted, anddescription of the forms of the transflective layer and a color filterwhich are the characteristic parts of the liquid crystal displayaccording to the eighth embodiment will be given in detail, withreference to the drawings.

Note that in the eighth embodiment, description will be made regarding acase of using illumination light wherein the luminance of wavelengthscorresponding to green is stronger that the luminance of otherwavelengths, and wherein the luminance of wavelengths corresponding toblue is weaker than the luminance of other wavelengths.

FIG. 32 is a diagram illustrating the transflective layer and colorfilter of the liquid crystal display according to the eighth embodiment,and is a diagram corresponding to FIG. 16(A) described in the fourthembodiment.

In FIG. 32, reference numeral 703 denotes a transflective layer. Thetransflective layer 703 has, for each pixel, transmissive areas 701formed by opening the metal film in window fashion for transmittinglight emitted from the back-light 5 or incident light from the uppersubstrate 3, and reflective area 702 (hatched diagonally upwards towardthe right in FIG. 32) for reflecting incident light from the uppersubstrate 3, as with the fourth embodiment.

However, unlike the fourth embodiment, in the present embodiment asshown in FIG. 32, the transflective layer 703 is such that the dimensionof the opening portions corresponding to each of the sub-pixels 751R,751G, and 751B, making up each pixel 751, that is to say, the dimensionof the transmissive areas 701R, 701G, and 701B, making up thetransflective layers 703R, 703G, and 703B, and the dimension of thereflective areas 702R, 702G, and 702B, are at dimension ratios accordingto the spectral properties of the illumination light emitted from theillumination device 5.

On the other hand, as with the fourth embodiment, the color filter isprovided for each of the pixels making up the display area, includingpigment layers 711 repeatedly arrayed in the order of the red layer711R, green layer 711G, and blue layer 711B, with the red layer 711R andgreen layer 711G and blue layer 711B extending so as to be orthogonal tothe transparent electrode 7 provided on the upper substrate 3.

As shown in FIG. 32, the pigment layers 711R, 711G, and 711B, areprovided on the entirety of the area overlapping the transmissive areas701R, 701G, and 701B of the transflective layers 703R, 703G, and 703B ina planar manner, and an area excluding a part of an area overlapping thereflective areas 702R, 702G, and 702B in a planar manner with thepigment layers 711R, 711G, and 711B opened in window forms. Accordingly,the color filter includes a pigment layer formation area where thepigment layers 711R, 711G, and 711B are formed, and pigment layernon-formation areas 711D, 711E, and 711F which are a part of an areaoverlapping with the reflective areas 702R, 702G, and 702B in a planarmanner and where the pigment layers 711R, 711G, and 711B are notprovided.

With the present embodiment, with regard to the sub-pixel 751G where thegreen layer (green color filter) 711G is formed, the dimension of thetransmissive area 701G corresponding thereto is smaller in comparison tothe sub-pixels 751R and 751B corresponding to the other colors.Conversely, with regard to the sub-pixel 751B where the blue layer (bluecolor filter) 711B is formed, the dimension of the transmissive area701B corresponding thereto is larger in comparison to the sub-pixels751R and 751G corresponding to the other colors.

Also, with this liquid crystal display, the dimension of the pigmentlayer formation area, i.e., the dimension of the pigment layers 711R,711G, and 711B is set to be smaller in the order of the blue layer7111B, the red layer 711R, and the green layer 711G.

With such a liquid crystal display, the display colors and brightnessare adjusted by performing both of the following first adjustment andsecond adjustment.

For the first adjustment, the brightness is adjusted such thattransmittance sufficient for obtaining bright light can be obtained inthe transmissive mode by changing the ratio of the transmissive areas701R, 701G, and 701B, and the reflective areas 702R, 702G, and 702B.

Also, the sub-pixel 751G where the green layer 711G is formed is made tobe smaller in comparison with the other sub-pixels 751R and 751B, andthe sub-pixel 751B where the blue layer 711B is formed is made to belarger in comparison with the other sub-pixels 751R and 751G, therebychanging the ratio of the transmissive areas 701R, 701G, and 701B, andthe reflective areas 702R, 702G, and 702B. Thus, there is sufficientlight of the wavelengths corresponding to the red light and blue lightwhich have comparatively low luminance in the illumination light passingthrough the transflective layer 703, while light with the wavelengthcorresponding to green which have comparatively high luminance isrestricted to pass through the transflective layer 703, therebyadjusting the color display.

For the second adjustment, the brightness is adjusted such thattransmittance sufficient for obtaining bright light in the reflectivemode can be obtained by changing the ratio of the dimension of thepigment layer formation area which is the dimension of the pigmentlayers 711R, 711G, and 711B, and the dimension of the pigment layernon-formation areas 711D, 711E, and 711F.

Also, the dimension of the pigment layers 711R, 711G, and 711B, is setto be smaller in the order of the blue layer 711B, the red layer 711R,and the green layer 711G, and the ratio of the dimension of the pigmentlayer formation area which is the dimension of the pigment layers 711R,711G, and 711B, as to the dimension of the pigment layer non-formationareas 711D, 711E, and 711F, is changed. Thus, the color properties ofthe color filter are adjusted, and display color is adjusted.

Note that display color in the reflective mode is changed in the firstadjustment by changing the dimension of the reflective areas 702R, 702G,and 702B accompanying changing the ratio of the transmissive areas 701R,701G, and 701B and the reflective areas 702R, 702G, and 702B. Even inthe event that the display color in the reflective mode has changed dueto the first adjustment, the second adjustment performs compensation,and change in the display color in the reflective mode due to the firstadjustment can be prevented from causing problems in the display colorin the actual reflective mode when the second adjustment is performed inconsideration of the change in display color by the first adjustment.

With the liquid crystal display according to the present embodiment,both the first adjustment which can be carried out by changing the ratioof the transmissive areas 701R, 701G, and 701B, and the reflective areas702R, 702G, and 702B, and the second adjustment which can be carried outby changing the ratio of the dimension of the pigment layer formationarea and the dimension of the pigment layer non-formation areas 711D,711E, and 711F, are performed, so in the event that the transmissiveareas 701R, 701G, and 701B are enlarged to improve transmittance in thefirst adjustment so that bright display can be obtained in thetransmissive mode, and the reflective areas 702R, 702G, and 702B becomesmall, reducing the dimension of the pigment layer non-formation areas711D, 711E, and 711F in the second adjustment allows reflectancesufficient for obtaining bright light in the reflective mode to beobtained. Accordingly, there is no problem that the display in thereflective mode becomes dark even in the event that the transmissiveareas 701R, 701G, and 701B are enlarged so that bright display can beobtained in the transmissive mode.

Thus, according to the above-described liquid crystal display,brightness can be effectively adjusted, and a bright display can be madeboth in the reflective mode and the transmissive mode.

With the liquid crystal display according to the present embodiment,both the first adjustment which can be carried out by changing the ratioof the transmissive areas 701R, 701G, and 701B, and the reflective areas702R, 702G, and 702B, and the second adjustment which can be carried outby changing the ratio of the dimension of the pigment layer formationarea and the dimension of the pigment layer non-formation areas 711D,711E, and 711F, are performed, so that display color can be effectivelyadjusted, and extremely excellent color reproduction can be obtained.

Specifically, with the liquid crystal display according to the presentembodiment, the effects which irregularities in spectral properties ofthe illumination light have on the observed light can be suppressed, andevent in the event that transmissive display is performed usingillumination light wherein the luminance of wavelengths corresponding tothe green light is greater than the luminance of the other wavelengths,and wherein the luminance of wavelengths corresponding to the blue lightis smaller than the luminance of the other wavelengths, situationswherein the image visually recognized by the observer is colored, can beavoided. In other words, as with the first embodiment, thenon-uniformity in the spectral properties of the illumination light iscompensated, thereby realizing good color reproduction.

Further, whereas the first embodiment is only adjustment of the displaycolor and brightness equivalent to the first adjustment in the presentembodiment, and the fourth embodiment is only adjustment of the displaycolor and brightness equivalent to the second adjustment in the presentembodiment, both the first adjustment and second adjustment areperformed with the liquid crystal display according to the presentembodiment, so that color reproduction can be improved even further, anda liquid crystal display with even more excellent display quality can berealized.

Moreover, with this liquid crystal display, pigment layer non-formationareas 711D, 711E, and 711F are formed at a part of the area overlappingthe reflective areas 702R, 702G, and 702B of the transflective layers703R, 703G, and 703B in a planar manner, so that part of the externallight incident onto the liquid crystal display in the reflective modepasses through the pigment layer non-formation areas 711D, 711E, and711F. Further, the light passing trough the color filter twice in thereflective mode is the sum of the uncolored light which has passedthrough the pigment layer non-formation areas 711D, 711E, and 711F andthe colored light which has passed through the pigment layers 711. Onthe other hand, the light which is incident from the back-light 5 in thetransmissive mode and passes through the transmissive areas 701R, 701G,and 701B, all passes through the pigment layer 711, so that lightpassing through the color filter once in the transmissive mode is allcolored. Accordingly, the difference in color concentration between thelight passing through the color filter twice in the reflective mode andthe light passing through the color filter once in the transmissive modecan be reduced.

Consequently, as with the fourth embodiment, a color transflectiveliquid crystal display capable of display with good coloring and highvisibility both in the reflective mode and transmissive mode can berealized.

With the ninth embodiment, the overall configuration of the liquidcrystal display is the same as the fifth embodiment shown in FIG. 17,and accordingly detailed description will be omitted.

Also, the liquid crystal display according to the ninth embodiment hasdifferent dimensions for the transmissive areas of the sub-pixels andalso is formed so that the dimensions of the pigment layer non-formationareas in the pigment layers differ, as with the above-described eighthembodiment. Accordingly, the liquid crystal display according to theninth embodiment differs from the liquid crystal display according tothe eighth embodiment only in the forms of the transflective layer andcolor filter. Accordingly, the transflective layer and the color filterwill be described in detail, with reference to the drawings.

FIG. 33 is a diagram illustrating the transflective layer and the colorfilter of the liquid crystal display according to the ninth embodiment,and is a diagram corresponding to FIG. 17(A) described with the fifthembodiment.

In FIG. 33, reference numeral 803 denotes a transflective layer. As withthe fifth embodiment, the transflective layer 803 is extended andprovided in a stripe form in the direction vertical to the paper so asto be orthogonal to the transparent electrode 7 provided on the uppersubstrate 3, and provided with the same pitch as the transparentelectrodes 8 provided on the lower substrate 2. Then, as shown in FIG.33, the width of the pattern of the transparent electrodes 8 provided onthe lower substrate 2 is formed so as to be greater than the width ofthe metal film pattern making up the transflective layer 803, so thatband-shaped areas where the metal film making up the transflective layer803 and the transparent electrodes 8 do not overlap in a planar mannerserve as transmissive areas 801, and the entire area where the metalfilm is provided serves as a reflective area 802 (hatched diagonallyupwards toward the right in FIG. 33).

However, unlike the fifth embodiment, with the present embodiment, asshown in FIG. 33, the transflective layer 803 is such that the areasalong the edges of the sub-pixels 851R, 851G, and 851B, making up eachpixel 851, that is to say, the dimension of the transmissive areas 801R,801G, and 801B, making up the transflective layers 803R, 803G, and 803B,and the dimension of the reflective areas 802R, 802G, and 802B, are atdimension ratios according to the spectral properties of theillumination light emitted from the illumination device 5.

On the other hand, as with the fifth embodiment, the color filter isprovided for each of the pixels making up the display area, includingpigment layers 811 repeatedly arrayed in the order of the red layer811R, green layer 811G, and blue layer 811B, with the red layer 811R,the green layer 811G, and blue layer 811B extending so as to beorthogonal to the transparent electrode 7 provided on the uppersubstrate 3.

As shown in FIG. 33, the pigment layers 811R, 811G, and 811B, areprovided on the entirety of the area overlapping the transmissive areas801R, 801G, and 801B of the transflective layers 803R, 803G, and 803B ina planar manner, and an area excluding a part of an area overlapping thereflective areas 802R, 802G, and 802B of the transflective layers 803R,803G, and 803B in a planar manner with the pigment layers 111R, 111G,and 111B opened in stripe forms.

Accordingly, the color filter includes a pigment layer formation areawhere the pigment layers 811R, 811G, and 811B are formed, and pigmentlayer non-formation areas 811D, 811E, and 811F which are a part of anarea overlapping with the reflective areas 802R, 802G, and 802B in aplanar manner and where the pigment layers 811R, 811G, and 811B are notprovided.

Also, in the present embodiment, with regard to the sub-pixel 851G wherethe green layer (green color filter) 811G is formed, the dimension ofthe transmissive area 801G corresponding thereto is smaller incomparison to the sub-pixels 851R and 851B corresponding to the othercolors, as with the eighth embodiment. Conversely, with regard to thesub-pixel 851B where the blue layer (blue color filter) 811B is formed,the dimension of the transmissive area 801B corresponding thereto isgreater in comparison to the sub-pixels 851R and 851G corresponding tothe other colors.

Also, with this liquid crystal display, the dimension of the pigmentformation area, i.e., the dimension of the pigment layers 811R, 811G,and 811B, is set so as to be smaller in the order of the blue layer811B, the red layer 811R, and the green layer 811G, as with the eighthembodiment.

With such a liquid crystal display as well, the display colors andbrightness can be adjusted by changing the ratio of the transmissiveareas 801R, 801G, and 801B, and the reflective areas 802R, 802G, and802B, and also by changing the ratio of the dimension of the pigmentlayer formation area and the dimension of the pigment layernon-formation areas 811D, 811E, and 811F. Accordingly, display color andbrightness can be effectively adjusted.

Consequently, as with the eighth embodiment, a liquid crystal displaycapable of bright display both in the reflective mode and intransmissive mode, and extremely excellent color reproduction can berealized.

Further, with this liquid crystal display as well, pigment layernon-formation areas 811D, 811E, and 811F are formed, so that thedifference in color concentration between the light passing through thecolor filter twice in the reflective mode and the light passing throughthe color filter once in the transmissive mode can be reduced, and acolor transflective liquid crystal display capable of display with goodcolorization and high visibility both in the reflective mode andtransmissive mode, can be realized.

It should be understood that the liquid crystal display according to thepresent invention is not restricted to the above-described embodiments,but rather may be arranged wherein, for example the transflective layeris formed of aluminum, and the pigment layer includes a blue layer and ared layer, wherein the dimension of the pigment layer formation area isset so as to be smaller for the blue layer than for the red layer. Withsuch a liquid crystal display, the dimension of the pigment layerformation area is set such as to be smaller for the blue layer than forthe red layer, so even in the event that the light reflected by thetransflective layer is colored blue due to the transflective layer beingformed of aluminum, the light is compensated by passing through thecolor filter twice. Accordingly, a liquid crystal display with excellentcolor reproduction and high display quality can be realized.

Also, an arrangement may be made wherein the transflective layer isformed of silver, and the pigment layer includes a red layer and a bluelayer, wherein the dimension of the pigment layer formation area is setsuch as to be smaller for the red layer than for the blue layer. Withsuch a liquid crystal display, the dimension of the pigment layerformation area is set such as to be smaller for the red layer than forthe blue layer, so that even in the event that the light reflected bythe transflective layer is colored yellow due to the transflective layerbeing formed of silver, the light can be compensated by passing throughthe color filter twice. Accordingly, a liquid crystal display withexcellent color reproduction and high display quality can be realized.

Also, with the liquid crystal display according to the presentinvention, the smoothing film may be formed so as to cover over thecolor filter as in the example shown in the above-described embodiments,but anything that will smooth the unevenness formed by the color filteris sufficient, and thus may be formed only on the pigment layernon-formation area of the color filter, for example. With an arrangementwherein the smoothing film is formed only on the pigment layernon-formation area of the color filter, and an overcoat layer isprovided over the smoothing film, the thickness of the overcoat layercan be made thinner as compared to arrangements wherein an overcoatlayer is provided without a smoothing film. Also, an arrangement may bemade wherein, for example, an overcoat layer is formed without asmoothing layer, wherein the unevenness formed by the color filter issmoothed by the overcoat layer, so that the overcoat layer also servesas a smoothing film.

Also, smoothing may be performed by embedding a smoothing film in thepigment layer non-formation area, as with the example described in theabove-described embodiment, but smoothing may be performed by forming atransparent layer separate from the smoothing film and embedding thepigment layer non-formation area, and then forming a smoothing film overthe transparent layer and the pigment layer formation area.

Also, the transflective layer refers to an article with reflectingfunctions provided with a transmitting portions, and needs not be asimple reflective layer. In other words, this may be a reflectivepolarizer with polarizing functions. Examples of reflective polarizersinclude circular polarizers using cholesteric liquid crystal,beam-splitter linear polarizers using Brewster's angle, wire grid linearpolarizers wherein a plurality of slits around 60 nm are formed in areflective layer, and so forth.

Also, though passive matrix liquid crystal displays can be given asexamples of liquid crystal displays to which the present invention canbe applied as with the above-described embodiments, the presentinvention is also applicable to active matrix liquid crystal displaysusing thin film diodes (TFD), thin film transistors (TFT), and so forth,as switching devices.

Next, description will be given regarding electronic apparatus includingthe liquid crystal display according to the above embodiments.

First, an example wherein the above-described liquid crystal display isapplied to the display unit of a cellular telephone will be described.FIG. 22 is a perspective view illustrating the configuration of thiscellular telephone. As shown in the figure, the cellular telephone 1032comprises a plurality of operating buttons 1321, an earpiece 1322, amouthpiece 1323, and along with these, a display unit 1324 using theliquid crystal display according to the present invention (only thefirst substrate 3 is shown in FIG. 22).

FIG. 23 is a perspective view illustrating an example of a wristwatch-type electronic device. In FIG. 23, reference numeral 1100 denotesthe main unit of the watch, and reference numeral 1101 denotes theliquid crystal display unit using the aforementioned liquid crystaldisplay.

FIG. 24 is a perspective view illustrating an example of a mobileinformation processing device such as a word processor, mobile personalcomputer, or the like. In FIG. 24, reference numeral 1200 denotes theinformation processing device, reference numeral 1202 denotes an inputunit such as a keyboard, reference numeral 1204 denotes the main unit ofthe information processing device, and reference numeral 1206 denotesthe liquid crystal display unit using the liquid crystal display.

Now, in addition to the cellular telephone shown in FIG. 22, thewristwatch-type electronic device shown in FIG. 23, and the personalcomputer shown in FIG. 24, examples of electronic apparatus includeliquid crystal televisions, viewfinder or monitor-viewing video cassetterecorders, car navigation devices, pagers, electronic notebooks,calculators, word processors, workstations, video phones, POS terminals,equipment comprising touch panels, and the like.

As described above, with the liquid crystal display according to thepresent invention, irregularities in spectral properties of theillumination light from the illumination device can be compensated andhigh color reproduction can be realized, which can be used to form anelectronic apparatus comprising a liquid crystal display with goodcoloring and high visibility both in the reflective mode andtransmissive mode, and accordingly this is particularly suitable forelectronic apparatuses that require high-quality in display.

Next, the advantages of the present invention will be made clear throughexamples, but it should be understood that the present invention is notlimited to the following embodiments. Also, the reflective film in thetest example 1 through the test example 4 is a silver alloy coloredyellow.

In a first test example, a liquid crystal display according to the fifthembodiment shown in FIG. 17 was fabricated, the dimension ratio of thetransmissive area and the reflective area was set at 17:19, anddimension ratio of the pigment layer non-formation areas 111D, 111E, and111F which are areas where the pigment layers 111R, 111G, and 111B, arenot formed, is further set such that the red layer 111D: the green layer111E: the blue layer 111F=4:14:6.

In a second test example, as shown in FIG. 25, a liquid crystal displaywas fabricated in the same manner as the liquid crystal displayaccording to the fifth embodiment shown in FIG. 17, except that thedimension ratio of the transmissive area and the reflective area was setat 17:19, and the dimension ratio of the pigment layer non-formationareas 112D, 112E, and 112F in the color filter 102 which are areas wherethe pigment layers 112R, 112G, and 112B, are not formed, is further setsuch that the red layer 112D:the green layer 112E:the blue layer112F=1:1:1.

In a third test example, as shown in FIG. 26, a liquid crystal displaywas fabricated in the same manner as the liquid crystal displayaccording to the fifth embodiment shown in FIG. 17, except that thedimension ratio of the transmissive area and the reflective area was setat 11:25, and that there are no pigment layer non-formation areas in thepigment layers 113R, 113G, and 113B of the color filter 103, and thatthe color properties of the color filter were optimized (the colorpurity was lowered) to give priority to the display in the reflectivemode.

Now, with regard to the above test example 1 through test example 3, thetest example 1 is an example of the present invention, and test example2 and test example 3 are comparative examples.

The light obtained in the reflective mode and in the transmissive modewas measured regarding the liquid crystal displays according to testexample 1 through test example 3 thus manufactured.

The results thereof are shown in Table 1, and FIG. 27 through FIG. 30.

FIG. 27 is a diagram illustrating the results of measuring the lightemitted from the liquid crystal display according to the test example 1,wherein FIG. 27(A) is a chromaticity diagram of the light obtained inthe reflective mode, and 27(B) is a chromaticity diagram of the lightobtained in the transmissive mode. Also, FIG. 28 is a diagramillustrating the results of measuring the light emitted from the liquidcrystal display according to the test example 2, wherein FIG. 28(A) is achromaticity diagram of the light obtained in the reflective mode, and28(B) is a chromaticity diagram of the light obtained in thetransmissive mode. Also, FIG. 29 is a diagram illustrating the resultsof measuring the light emitted from the liquid crystal display accordingto the test example 3, wherein FIG. 29(A) is a chromaticity diagram ofthe light obtained in the reflective mode, and 29(B) is a chromaticitydiagram of the light obtained in the transmissive mode.

TABLE 1 Reflective mode Transmissive mode White White Mode display Colorrange display Color range Properties reflectivity dimensiontransmittance dimension Test Example 1 26.3% 1.73 × 10⁻² 2.3% 1.50 ×10⁻² Test Example 2 26.2% 1.55 × 10⁻² 2.3% 1.50 × 10⁻² Test Example 334.1% 1.35 × 10⁻² 2.1% 0.50 × 10⁻²

Here, the term “color range dimension” means the dimension of a triangleformed by connecting the three points of the x, y coordinates of thered, green, and blue display colors on a CIE chromaticity diagram.

The liquid crystal display according to the test example 3 which is acomparative example has a narrow color range dimension for both thelight obtained in the reflective mode and the light obtained in thetransmissive mode, as can be seen from Table 1, FIG. 29, and FIG. 30.

Also, the liquid crystal display according to the test example 2 whichis a comparative example, has a color range dimension wider incomparison with the liquid crystal display according to the test example3 for both the light obtained in the reflective mode and the lightobtained in the transmissive mode, as can be seen from Table 1, FIG. 28,and FIG. 29. Moreover, there is sufficient white display reflectivity.However, with the light obtained in the reflective mode, the red displayis purplish.

In comparison, the liquid crystal display according to the test example1, which is an example of the present invention, has a color rangedimension wider in comparison with the liquid crystal display accordingto the test example 3 for both the light obtained in the reflective modeand the light obtained in the transmissive mode, as can be seen fromTable 1, FIG. 27, and FIG. 28, and has sufficient white displayreflectivity.

Further, the color range dimension for the light obtained in thereflective mode is also wider in comparison with the liquid crystaldisplay according to the test example 2. Moreover, as with the liquidcrystal display according to the test example 2, the color purity of thered display and blue display increases in the light obtained in thereflective mode.

Accordingly, it was confirmed that with the liquid crystal displayaccording to the test example 1 which is an example of the presentinvention, there is little difference in color concentration between thelight obtained in the reflective mode and the light obtained in thetransmissive mode, color reproduction is excellent, and there issufficient white display reflectivity.

Thus, it is clear that in comparison with the liquid crystal displaysaccording to the test example 2 and test example 3 which are comparativeexamples, the liquid crystal display according to the test example 1which is an example of the present invention has good coloring in boththe reflective mode and the transmissive mode, and that display withhigh visibility can be made.

In a fourth test example, a liquid crystal display according to aseventh embodiment shown in FIG. 20 and FIG. 21 was made, with thedimension ratio of the transmissive area and the reflective area at17:19, and further the dimension ratio of the area where the green layer114G is formed and the pigment layer non-formation area 111E where thegreen layer 114G is not formed was set at 7:1, using a color filter withthe spectral properties shown in FIG. 31 as the color filter. That is,in comparison to the liquid crystal display according to the testexample 1, the color purity of the green and the red color filters isincreased, and instead the color purity of the blue color filter islowered, thereby raising the transmittance.

Note that the above test example 4 is an example of the presentinvention.

The light obtained in the reflective mode and in the transmissive modewas measured regarding liquid crystal display according to the testexample 4 thus manufactured, in the same manner as with the liquidcrystal display according to the test example 1. The results thereof areshown in Table 2 and FIG. 30

FIG. 30 is a diagram illuztrating the result of measuring the lightemitted from the liquid crystal display according to the test example 4,wherein FIG. 30(A) is a chromaticity diagram of the light obtained inthe reflective mode, and FIG. 30(B) is a chromaticity diagram of thelight obtained in the transmissive mode.

TABLE 2 Reflective mode Transmissive mode White White Mode display Colorrange display Color range Properties reflectivity dimensiontransmittance dimension Test Example 4 26.0% 2.62 × 10⁻² 2.2% 2.65 ×10⁻²

As can be seen in Table 2 and FIG. 30, with the liquid crystal displayaccording to the test example 4, though the white display reflectivityand transmittance did not change much in comparison to the liquidcrystal display according to the test example 1, the color purity ofgreen increased, and the color range dimension for the light obtained inthe reflective mode and the light obtained in the transmissive mode wasalso improved a great deal.

Accordingly, providing a pigment layer non-formation area 114E only forthe green layer 114G that contributes to coloring of green, which is themost visually effective color, allows excellent colorization to beobtained, and deterioration of white display reflectivity due toproviding the pigment layer non-formation area 114E can be reduced.

Also, lowering the color purity of the blue color filter to raise thetransmittance, and providing the pigment layer non-formation area 114Eonly for the green layer 114G, improved the yellow coloring owing to thereflective layer in the reflective mode being silver.

In test examples 5-8, liquid crystal displays were fabricated, using theareas shown in Table 3 as the transmissive area, the pigment layerformation area which is the dimension of the pigment layers, and thepigment layer non-formation area.

Note that of the above test example 5 through test example 8, testexample 5 through test example 7 are examples of the present invention,and test example 8 is a conventional example.

Also, an example of the dimensions of the components for fabricating theliquid crystal display according to the test example 7 is shown in FIG.33. The units of dimensions of the components shown in FIG. 33 are inμm, with the sub-pixel pitch at 237×79 (μm), and the sub-pixel dimensionat 14784 μm².

TABLE 3 Test Test Test Test example 8 example 5 example 6 example 7Dimension of Red 5824 6496 6496 6272 transmissive area (μm²) Green 58244928 4928 4928 Blue 5824 6496 6496 6270 Dimension of pigment Red 89608288 7748 7072 layer formation area (μm²) Green 8960 6796 6256 4456 Blue8960 8288 8288 7344 Dimension of pigment Red 0 0 540 1440 layernon-formation area (μm²) Green 0 3060 3600 5400 Blue 0 0 0 720Reflectivity (%) 17.1 20.0 21.2 25.1 White display in x 0.306 0.3140.313 0.319 reflective mode y 0.335 0.327 0.325 0.324 Transmittance (%)3.0 3.0 3.0 3.0 White display in x 0.312 0.311 0.311 0.310 transmissivemode y 0.339 0.324 0.324 0.319

The white display x, y coordinates on the CIE chromaticity diagram inthe reflective mode and the transmissive mode, the reflectivity, and thetransmittance, were measured for the liquid crystal displays accordingto test example 5 through test example 8 thus fabricated. The resultsthereof are shown in Table 3.

With the liquid crystal display according to the test example 8, it canbe understood that the white display in the reflective mode and thewhite display in the transmissive mode are greenish. Also, it can beunderstood that the reflectivity is low, and that the display in thereflective mode is dark.

In comparison, with the test example 5, in the state that thetransmittance in the test example 8 was maintained, the width of thepattern of the metal film making up the transflective layer was adjustedto make the dimension of the transmissive area for the green smaller,and to make the dimension of the transmissive area for red and thetransmissive area for blue larger, and also a green pigment layernon-formation area was provided.

Consequently, with the test example 5, as shown in Table 3, thereflectivity improved in comparison with the test example 8, thegreenness of the white display in the reflective mode and thetransmissive mode was improved, coming closer to the ideal white displaycolor coordinates (x=0.310, y=0.316) on the CIE chromaticity diagram.

Also, with the test example 6, in the state that the transmittance inthe test example 8 and the dimension of the transmissive area in thetest example 5 were maintained, the green pigment layer non-formationarea was enlarged, and also a red pigment layer non-formation area wasprovided.

Consequently, with the test example 6, as shown in Table 3, thereflectivity improved even more in comparison with the test example 5,the greenness of the white display in the reflective mode was improvedeven further, coming even closer to the ideal white display colorcoordinates.

Also, with the test example 7, in the state that the transmittance inthe test example 8 and the dimension of the green transmissive area inthe test example 5 and the test example 6 were maintained, the greenpigment layer non-formation area was enlarged even further whilereducing the dimension of the red transmissive area and enlarging thedimension of the blue transmissive area, the red pigment layernon-formation area was enlarged, and a blue pigment layer non-formationarea was provided.

Consequently, with the test example 7, as shown in Table 3, thereflectivity improved even more in comparison with the test example 6with little change in the white display in the transmissive mode, comingeven closer to the ideal white display color coordinates for whitedisplay in the transmissive mode.

It was thus confirmed from the test example 5 through test example 8that securing transmittance whereby a bright display can be obtained inthe transmissive mode while enlarging the dimension of the pigment layernon-formation area allows sufficient reflectivity for a bright displayin the reflective mode to be obtained, and that a liquid crystal displaycapable of a bright display in both the reflective mode and transmissivemode can be obtained.

Also, it was confirmed that a liquid crystal display capable of displaywith excellent color reproduction in both the reflective mode andtransmissive mode can be obtained, by adjusting the dimension of thetransmissive area and the dimension of the pigment layer non-formationarea (pigment layer formation area).

In test example 9, a liquid crystal display according to an eightembodiment shown in FIG. 32 was fabricated wherein the transmissiveareas 701R, 701G, and 701B, the pigment layer formation area which isthe dimension of the pigment layers 711R, 711G, and 711B, and thepigment layer non-formation areas 711D, 711E, and 711F are the samedimension as the seventh embodiment shown in Table 3. Note that the testexample 9 is an example of the present embodiment.

Also, FIG. 32 shows an example of the dimensions of the components forfabricating the liquid crystal display according to the eighthembodiment including the same dimensions as those of the components forthe liquid crystal display according to the test example 7. The units ofdimension of the components shown in FIG. 32 are in μm, with thesub-pixel pitch at 237×79 (μm), and the sub-pixel dimension at 14784μm².

The reflectivity, white display in the reflective mode, thetransmittance, and the white display in the transmissive mode, were eachmeasured for the liquid crystal display according to the test example 9thus fabricated. Consequently, results the same as those of the seventhexample shown in Table 3 were obtained.

As shown in Table 3, with the liquid crystal display according to thetest example 9, in comparison with the test example 8, the reflectivityimproved, the greenness in the white display in the reflective mode andthe transmissive mode was improved, being closer to white.

Accordingly, it was confirmed with the liquid crystal display accordingto the eighth embodiment as well, as with the liquid crystal displayaccording to the ninth embodiment, that a liquid crystal display capableof display with excellent color reproduction in both the reflective modeand transmissive mode can be obtained, and regardless of the shape ofthe transmissive area and pigment layer non-formation area (pigmentlayer formation area), adjusting the dimension of the transmissive areaand pigment layer non-formation area (pigment layer formation area) foreach color enables a liquid crystal display capable of display withexcellent color reproduction in both the reflective mode andtransmissive mode to be obtained.

As described above, according to the present invention, the percentageof transmissive area in the sub-pixels is a percentage according to thespectral properties of the illumination light, so that even in the eventthat the spectral properties of the illumination light used fortransmissive display are not uniform, deterioration in colorreproduction due to this can be suppressed.

Also, with the liquid crystal display according to the presentinvention, the pigment layers are formed on the entirety of the areaoverlapping the transmissive area in a planar manner, and an areaexcluding a part of an area overlapping the reflective area in a planarmanner, with a pigment layer formation area where the pigment layers areformed, and a pigment layer non-formation area at a part of an areaoverlapping the reflective area in a planar manner, so that the lightpassing trough the color filter twice in the reflective mode is the sumof the uncolored light which has passed through the pigment layernon-formation area and the colored light which has passed through thepigment layer formation area.

On the other hand, light passing through the color filter once in thetransmissive mode is all colored. Accordingly, the difference in colorconcentration between the light passing through the color filter twicein the reflective mode and the light passing through the color filteronce in the transmissive mode can be reduced. Consequently, a colortransflective liquid crystal display capable of display with goodcoloring and high visibility both in the reflective mode andtransmissive mode can be realized.

Moreover, with the liquid crystal display according to the presentinvention, the dimension of the pigment layer formation area differsbetween at least one color pigment layer of the pigment layers andanother color pigment layer, so that the color properties of the colorfilter can be adjusted by changing the dimension of the pigment layerformation area, thereby improving color reproduction, and realizing aliquid crystal display with excellent display quality.

Also, with the liquid crystal display according to the presentinvention, a transparent film for smoothing the steps between thepigment layer formation area and the areas where the pigment layers areprovided is provided, so that adverse effects due to the steps betweenthe pigment layer formation area and the areas where the pigment layersare not provided can be prevented, thereby improving the reliability ofthe liquid crystal display.

1. An electro-optical device comprising: an electro-optical material;and a plurality of pixel regions separately controlling optical statesof the electro-optical material, the plurality of pixel regions beingarranged in a matrix with pixels aligned in a first direction and in asecond direction that intersects with the first direction, each pixelhaving a substantially rectangular shape with two opposing short sidesextending in the first direction, each pixel region having a lighttransmitting portion and a light reflecting portion; and lightreflectors provided for each pixel region, each light reflectorincluding the respective light reflecting portion and an aperture at thelight transmitting portion of the corresponding pixel region, theapertures in adjacent pixel regions having the same width in the firstdirection and a different two-dimensional area, each aperture havingfirst and second edges that oppose each other and that extend in thefirst direction, the first edges of apertures in adjacent pixel regionsbeing aligned in a straight line, and the second edges of apertures inadjacent pixel regions being out of alignment, in the first direction.2. The electro-optical device according to claim 1, wherein, at theadjacent pixel regions in the predetermined arrangement direction, pairsof end edges located at both ends of each of the light transmittingportions orthogonal to the predetermined arrangement direction arealigned with each other.
 3. The electro-optical device according toclaim 1, wherein a colored layer of a plurality of color tones has acolor filter arranged in a predetermined pattern in each pixel region,and the predetermined arrangement direction is a direction that thepixel regions, at which the colored layer of different color tones isdisposed, are adjacent to each other.
 4. The electro-optical deviceaccording to claim 1, wherein a plan view shape of the pixel regions isrectangular, and the predetermined arrangement direction is a directionin which a shorter side of each pixel region extends.
 5. Theelectro-optical device according to claim 1, wherein a plurality of thelight transmitting portions is provided in at least one of the pixelregions, and an end of one of the plurality of light transmittingportions disposed at a most peripheral edge side orthogonal to thepredetermined arrangement direction serves as the end edge.
 6. Anelectronic apparatus having an electro-optical device according to claim1 and control means for controlling the electro-optical device.